Interference management utilizing harq interlaces

The present application generally relates to wireless communication, and more specifically to improving communication performance, but is not limited thereto.

Wireless communication systems for providing various types of communication (voice, data, multimedia services, etc.) to a large number of users are widely deployed. As the demand for high-speed multimedia data services grows rapidly, the challenge of implementing efficient and robust communication systems with high performance arises.

To complement common mobile telephone network base stations, base stations in small service areas may be placed (eg, at the user's home) to provide a more robust indoor wireless service area for mobile phones. .. Base stations in such small service areas are commonly referred to as access point base stations, Home Node Bs, or femto cells. Typically, base stations in such small service areas are connected to the Internet and mobile network operators via DSL routers or cable modems.

The radio frequency (RF) service area of a base station in a small service area may not be optimized by some mobile operators, and such base station placement may be ad hoc, so the RF interference problem. May occur. In addition, soft handover may not be able to support base stations in small service areas. Therefore, there is a need for improved interference management for wireless networks.

35 U.SC Priority Claim under Article 119 This application is filed by the applicant on September 21, 2007, with reference number 071700P1 in the United States provisional patent application No. 60 / 974,428, and filed on September 21, 2007, with reference number 071700P2 in the United States. Provisional Patent Application No. 60 / 974,449, US Provisional Patent Application No. 60 / 974,794 with reference number 071700P3 filed on September 24, 2007, and Reference Number 071700P4 filed on October 3, 2007. It claims the interests and priority of US Provisional Patent Application No. 60 / 977,294, and the disclosure of each application is incorporated herein by reference.

The following is a summary of exemplary embodiments of the present disclosure. As used herein, it will be understood that this may refer to one or more aspects of the present disclosure.

The present disclosure relates, in some embodiments, to the use of partial reuse techniques to manage interference. For example, in some embodiments, the partial reuse is a hybrid automatic assigned to an uplink traffic or a downlink traffic. repeat-request) (HARQ) May include utilizing part of a set of interlaces. In some embodiments, partial reuse may include utilizing a portion of the time slot assigned to the uplink traffic or the downlink traffic. In some embodiments, partial reuse may include utilizing a portion of the frequency spectrum assigned to uplink traffic or downlink traffic. In some embodiments, partial reuse may include utilizing a portion of a set of spreading codes (such as SF16) assigned to uplink traffic or downlink traffic. In some embodiments, such parts may be defined and allocated so that neighboring nodes use resources that do not overlap. In some embodiments, the definition and allocation of such parts may be based on interference-related feedback.

The present disclosure relates to controlling interference using power management related techniques in some embodiments. For example, in some embodiments, the transmit power of the access terminal may be controlled to reduce interference at unrelated access points. In some embodiments, the noise figure or receive attenuation of the access point is controlled based on the received signal strength associated with the signal from one or more access terminals.

The present disclosure relates to managing interference using transmit power profiles and / or attenuation profiles, in some embodiments. For example, downlink transmit power or uplink receive continuation may vary dynamically at a node as a function of time. In this case, different nodes may use different phases of the profile to reduce interference between the nodes. In some embodiments, the profile may be defined based on interference-related feedback.

The above and other exemplary embodiments of the present disclosure will be described in the following detailed description and the appended claims, as well as in the accompanying drawings.

<figref num="1">It is a simplified block diagram which shows some exemplary aspects of a communication system.</figref><figref num="2">It is a simplified block diagram which shows some exemplary aspects of a component in an exemplary communication system.</figref><figref num="3">It is a flow diagram which shows some exemplary aspects of the operation which may be performed to manage the interference.</figref><figref num="4">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference utilizing HARQ interlaced-based partial reuse.</figref><figref num="5">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference using a transmit power profile.</figref><figref num="6">FIG. 6 is a simplified diagram showing some aspects of an exemplary transmit power profile.</figref><figref num="7">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference using a receive attenuation profile.</figref><figref num="8">FIG. 6 is a simplified diagram showing some aspects of an exemplary receive attenuation profile.</figref><figref num="9">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference using time slot-based partial reuse.</figref><figref num="10">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference using time slot-based partial reuse.</figref><figref num="11">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference utilizing frequency spectrum-based partial reuse.</figref><figref num="12">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference utilizing frequency spectrum-based partial reuse.</figref><figref num="13">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference using diffuse code-based partial reuse.</figref><figref num="14">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference using diffuse code-based partial reuse.</figref><figref num="15">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference using transmit power control.</figref><figref num="16">It is a simplified figure which shows some aspects of an exemplary power control function.</figref><figref num="17">FIG. 5 is a flow diagram illustrating some exemplary embodiments of operations that may be performed to manage interference by dynamically adjusting the damping factor.</figref><figref num="18">It is a simplified figure which shows the wireless communication system.</figref><figref num="19">It is a simplified figure which shows the wireless communication system which includes a femto node.</figref><figref num="20">It is a simplified figure which shows the service area of wireless communication.</figref><figref num="21">It is a simplified block diagram which shows some exemplary aspects of a communication component.</figref><figref num="22">FIG. 6 is a simplified block diagram showing some exemplary embodiments of an apparatus configured to manage interference as taught herein.</figref><figref num="23">FIG. 6 is a simplified block diagram showing some exemplary embodiments of an apparatus configured to manage interference as taught herein.</figref><figref num="24">FIG. 6 is a simplified block diagram showing some exemplary embodiments of an apparatus configured to manage interference as taught herein.</figref><figref num="25">FIG. 6 is a simplified block diagram showing some exemplary embodiments of an apparatus configured to manage interference as taught herein.</figref><figref num="26">FIG. 6 is a simplified block diagram showing some exemplary embodiments of an apparatus configured to manage interference as taught herein.</figref><figref num="27">FIG. 6 is a simplified block diagram showing some exemplary embodiments of an apparatus configured to manage interference as taught herein.</figref><figref num="28">FIG. 6 is a simplified block diagram showing some exemplary embodiments of an apparatus configured to manage interference as taught herein.</figref><figref num="29">FIG. 6 is a simplified block diagram showing some exemplary embodiments of an apparatus configured to manage interference as taught herein.</figref><figref num="30">FIG. 6 is a simplified block diagram showing some exemplary embodiments of an apparatus configured to manage interference as taught herein.</figref>

By convention, the various features shown in each drawing may not be on scale. Therefore, the dimensions of various features may be scaled up or down as appropriate for clarity. In addition, some drawings have been simplified for clarity. Therefore, each drawing may not show all the components of a given device (equipment, etc.) or method. Finally, similar reference numerals may be used to represent similar features throughout this specification and each figure.

Hereinafter, various aspects of the present disclosure will be described. It is clear that the teachings herein can be practiced in a wide variety of forms and that the specific structures, functions, or both disclosed herein are merely representative. It should be. Based on the teachings herein, one of ordinary skill in the art may implement one aspect disclosed herein independently of any other aspect, in which two or more of these aspects are in various ways. You should understand that they may be combined in. For example, one device or one method may be performed using any number of aspects set forth herein. In addition, such devices or methods are performed in addition to, or in addition to, one or more of the aspects set forth herein, using other structures, functions, or structures and functions. May be good. Further, one aspect may comprise at least one element of a claim.

In Figure 1, the placed nodes (access points 102, 104, 106, etc.) may be located in the relevant geographic area or may roam across the relevant geographic area (access). An exemplary embodiment of a communication system 100 when providing a wireless connection for terminals 108, 110, 112, etc.) is shown. In some embodiments, the access points 102, 104, and 106 may communicate with one or more network nodes (such as a centralized network controller such as network node 114) to facilitate WAN connectivity.

An access point, such as access point 104, may be restricted so that only one particular access terminal (such as access terminal 110) is allowed access to this access point, or it may be restricted in some other way. is there. In such a case, the restricted access point and / or the access terminal related thereto (access terminal 110, etc.) may be, for example, an unrestricted access point (macro access point 102, etc.), or an access terminal related thereto (access terminal, etc.). It may interfere with other nodes in the system 100, such as 108), another restricted access point (such as access point 106), or its associated access terminal (such as access terminal 112). For example, the access point closest to the predetermined access terminal may not be the service providing access point of this access terminal. Therefore, the transmission by this access terminal may interfere with the reception at the access terminal. As discussed herein, partial reuse, power control, and other techniques may be used to mitigate interference.

An exemplary operation of a system, such as System 100, will be discussed in more detail along with the flow diagram in Figure 2. For convenience, the operation of FIG. 2 (or any other operation discussed or taught herein) may be by a particular component (such as a component of system 100 and / or a component of system 300 shown in FIG. 3). Explained to be done. However, it should be understood that these actions may be performed by different types of components and may be performed using different numbers of components. It should also be understood that one or more of the operations described herein may not be used in a given implementation.

For illustration purposes, various aspects of the disclosure will be described in the context of interacting network nodes, access points, and access terminals. However, it should be understood that the teachings herein may be applicable to different types of devices or devices referred to in different terms.

FIG. 3 shows some exemplary components that can be incorporated into network nodes 114 (such as wireless network controllers), access points 104, and access terminals 110 as taught herein. It should also be understood that the components shown for a given one of these nodes may be incorporated into other nodes in the system 100.

The network node 114, the access point 104, and the access terminal 110 include transceivers 302, 304, and 306 that interact with each other and also with other nodes, respectively. The transceiver 302 includes a transmitter 308 that sends a signal and a receiver 310 that receives the signal. The transceiver 304 includes a transmitter 312 that sends a signal and a receiver 314 that receives the signal. The transceiver 306 includes a transmitter 316 that sends a signal and a receiver 318 that receives the signal.

In a typical implementation, the access point 104 interacts with the access terminal 110 via one or more wireless communication links and with the network node 114 via a backhaul. It should be understood that wireless or non-wireless links may be used between these nodes or between other nodes in various implementations. Therefore, transceivers 302, 304, and 306 may include wireless and / or non-radio communication components.

The network node 114, access point 104, and access terminal 110 also include various other components that may be used in conjunction with the interference management taught herein. For example, the network node 114, the access point 104, and the access terminal 110 may include interference controllers 320, 322, and 324, respectively, which reduce interference and provide other related functions as taught herein. Interference controllers 320, 322, and 324 may include one or more components that perform certain types of interference management. The network node 114, access point 104, and access terminal 110 may include communication controllers 326, 328, and 330, respectively, that manage communication with other nodes and provide other related functions as taught herein. Good. The network node 114, access point 104, and access terminal 110 may include timing controllers 332, 334, and 336, respectively, that manage communication with other nodes and provide other related functions as taught herein. Good. Other components shown in Figure 3 will be discussed later.

For illustration purposes, the interference controllers 320 and 322 are illustrated as including several controller components. However, in practice, certain implementations may not use all of these components. Here, the HARQ controller component 338 or 340 may provide functions related to the HARQ interlaced operation taught herein. Profile controller components 342 or 344 may provide functions related to transmit power profiles or receive attenuation operations as taught herein. The time slot controller component 346 or 348 may provide functions related to the operation of the time slot portion taught herein. The spectrum mask controller component 350 or 352 may provide functions related to the spectrum mask operation taught herein. Diffuse code controller components 354 or 356 may provide functions related to the spread code operation taught herein. The transmit power controller component 358 or 360 may provide functions related to transmit power operation as taught herein. Damping factor controller components 362 or 364 may provide functionality related to damping factor operation as taught herein.

FIG. 2 shows how network nodes 114, access points 104, and access terminals 110 may interact with each other to achieve interference management (interference mitigation, etc.). In some embodiments, these actions may be used on the uplink and / or the downlink to reduce interference. In general, one or more techniques shown in FIG. 2 may be used in more specific implementations described below in conjunction with FIGS. 4-18. Therefore, for the sake of clarity, these more specific implementations may not revisit these techniques.

As represented by block 202, network node 114 (such as interference controller 320) may optionally define one or more interference management parameters for access point 104 and / or access terminal 110. Such parameters may take various forms. For example, depending on the implementation, network node 114 may define partial reuse parameters to mitigate interference in uplinks and / or downlinks. As described herein, such partial reuse may include one or more of HARQ interlacing, puncturing, frequency spectra, or diffusion codes. Depending on the implementation, the network node 114 may define different types of interference management information, such as transmit power parameters and receive attenuation parameters. Examples of such parameters will be described in more detail below together with FIGS. 4 to 18.

In some embodiments, the definition of an interference parameter may include determining how to allocate one or more resources. For example, the operation of block 402 may include defining how allocated resources (such as the frequency spectrum) may be divided for partial reuse. In addition, the definition of partial reuse parameters is utilized by any one of the set of access points (such as restricted access points) by how many of the allocated resources (eg, how many HARQ interlaces, etc.) It may also include deciding whether it may be done. The definition of the partial reuse parameter may also include determining how much of the resource may be utilized by a set of access points (such as restricted access points).

In some embodiments, network node 114 may have interference in the uplink or downlink, and if there is interference, parameters may be defined based on received information indicating the extent of such interference. Good. Such information may be received from various nodes in the system (eg, access points and / or access terminals) in different ways (eg, via backhaul, wirelessly, etc.).

For example, in some cases, one or more access points (such as access point 104) monitor (monitor) the uplink and / or the downlink and display (repeatedly,) the interference detected on the uplink and / or the downlink. Or send to network node 114 (or on request). To give an example of this, the access point 104 calculates the signal strength of a signal received from a nearby access terminal (such as the access terminal 108 or 112) that is not associated with the access point 104 (eg, is not serviced by it). You may then report this to network node 114.

In some cases, each access point in the system may generate a load display when it is under a relatively high load. Such a display may take, for example, a busy bit in 1xEV-DO, a relative grant channel (RGCH) in 3GPP, or any other suitable form. In a traditional scenario, the access point can send this information over a downlink to its associated access terminal. However, such information may also be transmitted to network node 114 (via backhaul, etc.).

In some cases, one or more access terminals (eg, access terminals 110) may monitor the downlink signal and provide information based on this monitoring. The access terminal 110 may transmit such information to the access point 104 (for example, this information may be transferred to the network node 114) or to the network node 114 (via the access point 104). .. Other access terminals in the system may send information to network node 114 in a similar manner.

In some cases, the access terminal 110 may generate a measurement report (eg, on a repeating principle). Depending on the embodiment, such a measurement report may include from which access point the access terminal 110 is receiving the signal, the received signal strength display associated with the signal from each access point (eg, Ec / Io), and each access point. Propagation loss, or other suitable type of information may be displayed. In some cases, the measurement report may include information related to any load display received by the access terminal 110 over the downlink.

Network node 114 then uses the information from one or more measurement reports to see if access point 104 and / or access terminal 110 is relatively close to another node (such as another access point or access terminal). You may judge. In addition, network node 114 may also use this information to determine if any of these nodes interferes with any other of these nodes. For example, the network node 114 may determine the received signal strength at a node based on the transmission power of the node that transmitted the signal and the propagation loss between these nodes.

In some cases, the access terminal 110 may generate information that displays a signal and interference to noise ratio, SINR, etc. on the downlink. Such information may include, for example, a channel quality indication (CQI), a data rate control (DRC) display, or other suitable information. In some cases, this information may be sent to access point 104, which may forward this information to network node 114 for use in interference management operations. In some embodiments, the network node 114 uses such information to determine if interference occurs on the downlink, or if interference within the downlink is increasing or decreasing. You may.

In some cases, interference-related information may be used to determine how to deploy partial reuse to mitigate interference, as shown in more detail below. For example, CQI or other relevant information is received for each HARQ interlace, which determines which HARQ interlace is associated with the lowest level of interference. Similar techniques may be used for other partial reuse techniques.

It should be understood that network node 114 may define parameters in various other ways. For example, in some cases, network node 114 may randomly select one or more parameters.

As represented by block 204, network node 114 (such as communication controller 326) sends defined interference management parameters to access point 104. As discussed below, in some cases the access point 104 uses these parameters and in some cases forwards these parameters to the access terminal 110.

In some cases, network node 114 may also manage interference in the system by defining interference management parameters that should be used by two or more nodes in the system (such as access points and / or access terminals). Good. For example, in the partial reuse scheme, network node 114 sets different (eg, mutually exclusive) interference management parameters close enough to neighboring access points (potentially interfering with each other). You may send it to a certain access point, etc.). As a specific example, the network node 114 assigns the first HARQ interlace to the access point 104 and the second HARQ interlace to the access point 106. In this way, communication at one restricted access point does not substantially interfere with communication at another restricted access point. Similar techniques may be used for other partial reuse schemes as well as for access terminals in the system.

As represented by block 206, the access point 104 (eg, the interference controller 322) determines the interference management parameters that it may use or may be transmitted to the access terminal 110. If the network node 114 defines an interference management parameter for the access point 104, this decision operation simply accepts the specified parameter and / or retrieves the specific parameter (eg, from data memory). It only contains.

In some cases, the access point 104 determines its own interference management parameters. These parameters can be similar to those described above in connection with block 202. In addition, in some cases, these parameters may be determined in the same manner as described above in block 202. For example, the access point 104 may receive information (eg, measurement report, CQI, DRC) from the access terminal 110. In addition, the access point 104 may monitor uplinks and / or downlinks to determine interference on these links. The access point 104 may also randomly select parameters.

In some cases, the access point 104 may work with one or more other access points to determine interference management parameters. For example, in some cases, the access point 104 interacts with the access point 106 to determine which parameters are being used by the access point 106 (thus selecting different parameters) or different (eg, mutually exclusive). The use of parameters may be negotiated. In some cases, the access point 104 determines if the access point 104 may interfere with another node (for example, based on CQI feedback indicating that another node is using the resource). However, if they may interfere, their interference management parameters may be defined to mitigate such potential interference.

As represented by block 208, the access point 104 (such as the communication controller 328) can send interference management parameters or other relevant information to the access terminal 110. For example, in some cases, this information is how partial reuse is arranged on the uplink or downlink between the access point 104 and the access terminal 110 (eg, which HARQ interlace should be used). , Which spectrum mask should be used, etc.). In some cases, this information can also be related to power control (eg, specifying uplink transmit power).

Thus, the access point 104 may transmit to the access terminal 110 on the downlink, or the access terminal 110 may transmit to the access point 104 on the uplink, as represented by blocks 210 and 212. Here, the access point 104 may transmit on the downlink and / or receive on the uplink using its interference management parameters. Similarly, the access terminal 110 may take these interference management parameters into account when receiving on the downlink or transmitting on the uplink.

Depending on the implementation, the access terminal 110 (eg, interference controller 306) may define one or more interference management parameters. Such parameters may be used by the access terminal 110 and / or sent to the access point 104 (eg, by the communication controller 330) and (eg, for use during uplink operation).

Next, with reference to FIG. 4, the operation related to the use of the partial reuse method using HARQ interlace on the uplink or downlink will be described in more detail. In some embodiments, the system 100 may also use time division multiplexing to transmit information over one or more defined time slots. Such time slots take various forms and / or may be referred to in various terms. For example, in various implementations, time slots are associated with, or are referred to by, frames, subframes, slots, transmission time intervals (TTI), HARQ interlaces, and the like. You may. For example, a given number of time slots (such as TTI) 1 to 16 may be monitored and used for downlink transmission. A similar method may be used for uplink transmission.

Based on the traffic on the monitored slots and the associated interference level, and based on one or more applications of the schemes taught herein, uplink or downlink transmission is the total number of slots M (eg, M = 16). It may be limited to a smaller defined number of slots N (eg, N = 8). Depending on the embodiment, such a partial reuse method may utilize HARQ interlace.

In a conventional 1xEV-DO system, each HARQ process, for example, HARQ retransmission of the original transmission in subframe "n", lines in slots (n + 4), (n + 8), (n + 12), etc. As such, it may be assigned every 4 subframes. To give a specific example, subframes 1, 5, 9, and the like may be assigned to HARQ interlace 1. If the original data transmission of HARQ interlace 1 in subframe 1 fails, a negative acknowledge (NACK) signal is output on the complementary link (such as the uplink in the case of downlink HARQ transmission). May be sent. The data is then retransmitted in subframe 5 of the same HARQ interlace 1, and if the transmission is successful, an acknowledgment (ACK) signal is received (via uplinks, etc.). Similar operations may be performed by other HARQ processes in other HARQ interlaces 2, 3, and 4.

In some embodiments, the partial reuse scheme can be configured to utilize HARQ interlace to transmit neighboring nodes (such as access points and / or access terminals) at different times. For example, the first access point transmits at HARQ interlaces 1 and 2, and the second access point transmits at HARQ interlaces 3 and 4. As a result, the interference that may normally occur between nodes may be reduced.

As represented by block 402 in FIG. 4, network node 114 (eg, HARQ control component 338 of interference controller 320) uses how many HARQ interlaces by each access point (eg, in a set of restricted access points). Decide if it's okay. For example, a defined number of HARQ interlaces of less than the total number of HARQ interlaces of "M" assigned to this set, "N", have one or more accesses in the system (eg, as described above in connection with Figure 2). It may be determined based on interference-related feedback from points and / or access terminals. Thus, at any given time, N of the total M HARQ interlaces, N downlink (or uplink) HARQ interlaces, are based on the downlink (or uplink) activity of neighboring nodes in the M HARQ interlaces. May be defined.

N can be a fixed value or can be dynamically defined. For M = 4, N is the minimum value N greater than 0_MINMaximum value N less than 4_MAXMay be set dynamically between. In some cases, the value N may be randomly determined. However, in general, the value N may be chosen to more effectively reduce interference between nodes in the system. The determination of the value N can be based on various criteria.

For example, one criterion is how access points are arranged (distributed) in the system (eg, total number of access points, density of access points within a given area, relative proximity of access points, etc.). Can be related to. Here, if there are many nodes that are close to each other, a smaller value of N may be used so that neighboring nodes are less likely to use the same HARQ interlace. Conversely, if the system has only a few nodes, a larger value of N may be defined to improve communication performance (throughput, etc.).

Another criterion may be regarding the traffic processed by each access point (eg, the amount of traffic, the type of traffic, the service quality requirements of traffic). For example, one type of traffic may be more susceptible to interference than another type of traffic. In such cases, a smaller value of N may be used. In addition, some traffic may have more stringent throughput requirements (although less sensitive to interference), so larger values of N may be used.

In some cases, network node 114 may define the value N based on the interference-related information received (eg, as discussed in FIG. 2). For example, the number of access points contacted by a given access terminal and the relative proximity of the access points to this access terminal may be determined based on the measurement report received from this access terminal. In this way, network node 114 determines if transmission in a given cell (eg, by a restricted access point or its associated access terminal) may interfere with neighboring cells, and defines N accordingly. You may.

Network node 114 may also define N based on interference information received from one or more access points (eg, as discussed in FIG. 2). For example, if the interference value is high, a smaller value N may be defined. In this way, the number of HARQ interlaces used by a given access point may be reduced. This reduces the probability of interference in each set of N HARQ interlaces out of the total M of HARQ interlaces.

In some cases, network node 114 may specify a particular HARQ interlace used by a particular access point, as represented by block 404. For example, network node 114 may determine the amount of interference that may be known at each of the M HARQ interlaces by a given access point and assign HARQ interlaces with lower interference to this access point. To give a specific example, network node 114 has access associated with access point 104 by downlink transmission by access point 106 on two HARQ interlaces (eg, interlaces 3 and 4) used by network node 114. It may be determined that it may interfere with reception at the terminal. This may be determined, for example, on the basis of downlink interference related information that network nodes may acquire as discussed herein. Network node 114 may then specify HARQ interlaces 1 and 2 for use by access point 104.

As mentioned above, the determination of interference at each HARQ interlace may be based on the signal received by network node 114. For example, the likelihood of internode interference may be determined based on one or more measurement reports received from one or more access terminals, as discussed herein. In addition, in the downlink, the access terminal in the system has the channel quality display (CQI) or data transfer rate control (DRC) information for each HARQ interrace (for example, for each TTI in 3GPP). May be generated and this information transferred to network node 114. In the downlink, the access terminal may monitor the downlink and provide interference-related information for each HARQ interlace (for example, for each TTI). Similarly, in the uplink, the access terminal may monitor the uplink and provide interference-related information on a per HARQ interlace (eg, per TTI). In some cases (eg, DRC feedback in 3GPP2), feedback from the access terminal may not provide a per-HARQ interlaced decision. In such cases, ACK / NACK feedback or some other type of feedback may be employed to identify the desired set of HARQ interlaces. As another example, the downlink data rate may be adjusted in a given HARQ interlace to determine the speed at which the access terminal can successfully decode the data (eg, with a given accuracy). Based on the optimal data rate determined for each HARQ interlace, it may be assumed which HARQ interlace provides optimal performance for a given access point. Alternatively, a centralized HARQ interlace selection scheme may be used (eg, when a network node specifies HARQ interlace for neighboring nodes as discussed herein).

In some embodiments, the designation of a particular HARQ interlace by network node 114 may depend on whether the corresponding uplink or downlink traffic is synchronized. Such synchronization may be achieved, for example, by using adjustments such as Tau-DPCH (DPCH relates to a dedicated physical communication path) or other suitable synchronization scheme.

In some embodiments, network node 114 may specify contiguous HARQ interlace for a given access point. In this way, at least a portion of the specified HARQ interlace may not be interfered with if the uplink or downlink traffic of different nodes is not synchronized. For example, if HARQ interlaces 1-4 are assigned to the first access point and HARQ interlaces 5-8 are assigned to the second access point, these access points will not be timed to each access point. Even in this case, at least three of the HARQ interlaces will not be interfered with by other access points.

As represented by block 406, network node 114 then sends the HARQ interlaced parameters it defines for one or more access points. For example, network node 114 may send node-specific specifications to each access point or may send common specifications to all access points in the set of access points.

As represented by block 408, access point 104 (eg, HARQ control component 340 of interference controller 322) determines the HARQ interlace it uses for uplink or downlink communication . Here, the access point 104 receives the value N from the network node 114. If network node 114 specifies the HARQ interlace used by the access point 104, the access point 104 may simply use these HARQ interlaces. In some cases, the access point 104 may randomly select parameters.

If the HARQ interlace is not specified by the network node 114 or is randomly selected, the access point 104 may decide which N HARQ interlaces to use based on appropriate criteria. Thus, initially this decision is based on (eg, constrained) the value N. In some cases, the access point 104 may define or adapt N (eg, based on criteria as described above).

In some cases, the access point 104 may choose the HARQ interlace associated with the least interference. In this case, the access point 104 may determine which HARQ interlace to use, similar to the method described above. For example, the access point 104 may receive information (eg, measurement report, CQI, DRC) from the access terminal 110. In addition, the access point 104 may monitor uplinks and / or downlinks to determine interference on these links. For example, the access point 104 may monitor uplink interference (load) from outside the cell when it is idle. In this way, the access point 104 may choose HARQ interlace to provide minimal out-of-cell interference.

In some cases, the access point 104 may work with one or more other access points to determine the HARQ interlace used by the access point 104. For example, access point 104 and access point 106 may negotiate to use different (eg, mutually exclusive) HARQ interlaces.

As represented by block 410, the access point 104 may determine a timing offset for use in uplink or downlink communication. For example, the access point 104 may continuously monitor the link over a period of time to roughly determine when neighboring nodes start and end sending it. In this way, the access point 104 may determine (eg, estimate) the time slot timing of neighboring nodes. The access point may then synchronize its uplink or downlink time slot timing with this time. In some embodiments, this may include defining Tau-DPCH parameters.

In some cases (for example, in 3GPP), each access point has these timings (HS-PDSCH) by time matching these P-CCPCHs (primary-common control physical channels). Timing etc.) may be synchronized. Such synchronization is, for example, timing signaling between GPS components at each access point, access points (eg, which may be relatively effective at neighboring access points some tens of meters away from each other). , Or some other technique may be used.

In some cases (such as HSDPA), the overhead is relatively high and may not be orthogonal to the traffic. In this case, discontinuous transmission or reception (DTX or DRX) may be used and no overhead may be transmitted during the DTX / DRX period. In such cases, transmission over CCPCH and EHICH is considered and each access terminal may be configured to match the lower CPICH Ec / Io measurements received from the access point using the DTX / DRX.

As represented by block 412, the access point 104 may send a message to the associated access terminal to inform which HARQ interlace will be used for the uplink or downlink. In some implementations, the access point 104 uses E-AGCH (enhanced-absolute grant channel) or some other similar mechanism to send HARQ interlaced specifications to its associated access terminal. May be good. For example, the access point 104 may set Xags = 1 to identify which TTI the access terminal uses. In addition, the access point 104 may send a display of the timing offset (eg, Tau-DPCH) determined in block 410 to the access terminal. In this way, the access point may schedule data transmission (uplink or downlink) in the optimal N of the M HARQ interlaces available (block 414).

The aforementioned HARQ interlace parameters (eg, N specific HARQ interlaces used by a given node) may be adjusted over time (over time). For example, the above information may be collected repeatedly and the parameters may be adjusted accordingly (using hysteresis and / or slow filtering as needed). In this way the HARQ interlace may be arranged to meet the current interference conditions in the system.

Depending on the implementation, HARQ interlaces may be assigned hierarchically. For example, if no restricted access points are located within the macro access point's service area, a full set of HARQ interlaces (eg, 8) is assigned to the macro access point. However, if the restricted access point is located within the service area of the macro access point, one part of the HARQ interlace (eg, 5) is assigned to the macro service area and another part of the HARQ interlace (eg, 5). , 3) may be assigned to restricted access points. The HARQ interlace assigned to the restricted access points may then be assigned between the restricted access points as described above (eg, N = 1). The number of HARQ interlaces assigned in this way may be defined based on various criteria as discussed herein (eg, restricted access point placement, traffic, interference, etc.) (in a fixed manner). Or dynamically adjusted, etc.). For example, as the number of restricted access points in the system or the amount of traffic at the restricted access points increases, so does the number of HARQ interlaces assigned to these access points.

Next, with reference to FIGS. 5 and 6, the operation relating to the use of a method of varying the transmission power (such as downlink transmission power) over time to reduce interference will be described in more detail. In some embodiments, the scheme comprises defining a transmit power profile, such as profile 602, shown in FIG. 6, which defines different power levels over time. Such profiles may take various forms and be defined in different ways. For example, in some cases, a profile may consist of a set of values that define transmit power for different time points. In some cases, the profile may be defined by an expression (eg, a sinusoidal waveform). Depending on the aspect, the profile may be periodic. As shown in FIG. 6, a maximum value (MAX), a minimum value (MIN), and a period 604 may be defined for the profile.

The transmit power profile may be used to control transmit power in various ways. For example, in some cases, the transmit power profile is used to control the total transmit power. Depending on the implementation, the overhead communication path (for example, CPICH) and the dedicated communication path may operate with a constant power. In that case, the residual power according to the transmission power profile may be shared among other communication paths (HS-SCCH, HS-PDSCH, etc.). Depending on the implementation, the overhead channel may be scaled.

In some embodiments, transmit power-based partial reuse may be achieved using a transmit power profile, as described in more detail below. For example, neighboring access points may use the same profile (or similar profile) based on different phases of this profile. For example, the first access point sends according to the profile shown in FIG. 6, and the second access point sends using the same profile that is 180 degrees shifted. Therefore, when the first access point is transmitting at the maximum power, the second access point may transmit at the minimum power.

As represented by block 502 in FIG. 5, network node 114 (such as profile control component 342 of interference controller 320) defines transmit power profile information that should be used for wireless transmission (such as over a downlink). For example). This information may include parameters such as transmission power profile, initial minimum and maximum values, and initial period value.

In some cases, one or more of these parameters may be predefined or randomly determined. However, these parameters are usually chosen to more effectively reduce interference between nodes in the system. The determination of this information is, for example, one or more measurement reports from one or more access terminals, one or more reports from one or more access points regarding CQI reported by one or more related access terminals, active access terminals. It can be based on various criteria such as the number of (active access terminals), the average downlink traffic at each access point (eg, within each cell), and so on.

To give a specific example, the definition of the transmit power profile parameter is how the access points are arranged in the system (for example, the total number of access points, the density of access points within a given area, and the relative access points. It can be based on proximity, etc.). Here, if there are many nodes that are close to each other, the parameters may be defined so that the neighboring nodes are less likely to transmit at the same time with high output. For example, the transmit power profile may be formed such that a given access point may transmit at maximum or near maximum output over a relatively short period of time. In this way, the transmit power profile provides proper isolation when a large number of phase values (eg, 60 degrees, 120 degrees, etc.) are used in connection with the transmit power profile by various nodes in the system. You may. Conversely, if there are only a few nodes in the system, the parameters may be defined to increase communication performance (throughput, etc.). For example, the transmit power profile may be formed such that a given access point may transmit at maximum or near maximum output over a longer period of time.

Also, different levels of isolation between neighboring access points (eg, cells) may be achieved by adjusting the magnitude of the minimum and maximum parameters. For example, if the MAX / MIN ratio is higher, better separation is achieved at the expense of longer transmissions when the access terminal transmits at lower power levels.

The transmit power profile parameters may be defined based on the traffic processed by each access point (eg, traffic load, traffic type, traffic quality requirements). For example, one type of traffic may be more susceptible to interference than another type of traffic. In such cases, parameters that provide a higher degree of isolation (eg, as described above) may be used (eg, transmit power profile or MAX / MIN). In addition, some traffic may have more stringent throughput requirements (although less sensitive to interference), which allows more transmission at higher power levels (eg, as mentioned above). The transmit power profile that enables it may be used.

In some cases, network node 114 has a transmit power profile based on receive interference related information (eg, feedback from one or more access points and / or access terminals in the system, as described above in connection with FIG. 2). Parameters may be defined. For example, the number of access points contacted by a given access terminal and the relative proximity of the access points to the access terminal may be determined based on the measurement report received from the access terminal. In this way, network node 114 may determine if transmission in a given cell (eg, a cell associated with a restricted access point) interferes with neighboring cells and adjust the power profile parameters accordingly. .. Network node 114 may also define parameters based on interference information received from one or more access points (eg, as discussed in FIG. 2).

Depending on the implementation, the periodic parameters are the delay sensitivity of application data (such as VoIP) and the CQI / DRC filtering / delay (from the time the SINR is measured to the time this SINR is enabled in the access point's traffic scheduler. It may be defined based on a trade-off with (such as delay). For example, if each cell carries a large amount of VoIP traffic, the period may be set to correspond to the periodicity of the VoIP packet. In some cases, cycles in the range of 50-100 milliseconds may be applicable. Depending on the implementation, the periodic parameters may be defined based on the number of access terminals receiving the service.

In some cases, as represented by block 504, network node 114 may specify a particular phase offset value used by a particular access point. For example, network node 114 may determine the amount of interference that a given access point may see when using different values of phase offset (eg, based on the CQI report received per TTI). Good. In this case, the phase offset associated with the lowest interference at this access point is assigned to this access point.

In addition, the network node 114 may specify a phase offset value for neighboring nodes so as to reduce interference between the nodes. To give a specific example, network node 114 may determine that downlink transmission by access point 106 may interfere with reception at access terminals associated with access point 104. This may be determined, for example, on the basis of downlink interference related information that may be acquired by network node 114 as discussed herein. In this case, network node 114 may specify different (eg, 180 degree out of phase) phase offset values for access points 104 and 106.

As represented by block 506, network node 114 then sends the power profile information it defines to one or more access points. Here, the network node 114 may send a node-specific designation to each access point, or the network node 114 may send a common designation to all access points in the set of access points.

As represented by blocks 508 and 510, access point 104 (eg, profile control component 344 of interference controller 322) determines the transmit power profile parameters it uses for downlink communication. If network node 114 specifies all transmit power profile parameters used by access point 104, access point 104 may simply use these parameters. In some cases, the access point 104 may randomly select parameters (eg, phase offsets).

If all parameters are not specified by network nodes 114 or are randomly selected, the access point 104 may decide which parameters to use based on appropriate criteria. In a typical case, the access point performs a tracking algorithm to dynamically determine the phase offset value that the access point 104 uses in conjunction with the transmit power profile, minimum, maximum, and periodic parameters received from network node 114. You may decide.

In some cases, the access point 104 may choose the phase offset value associated with the lowest interference. Here, the access point 104 may determine which phase offset value to use, as in the manner described above. For example, in block 508, the access point 104 may receive information (eg, measurement report, CQI, DRC) from the access terminal 110 and / or the access point 104 links to determine interference on the link. You may monitor it. As an example of the latter case, the access point 104 may monitor interference (load) from outside the cell on the downlink when it is idle. In this way, the access point 104 may select the phase offset value that gives the least out-of-cell interference at block 510.

In some cases, the access point 104 may work with one or more other access points to determine the phase offset value. For example, access point 104 and access point 106 may negotiate to use different (eg, out-of-phase) phase offset values. In such a case, the operation of the block 508 does not have to be performed.

As represented by block 512, the access point transmits on the downlink based on the current transmit power profile. Thus, the transmit power may fluctuate over time in a way that may reduce interference with neighboring nodes.

The transmission power profile parameters described above, such as the maximum, minimum, and periodic parameters defined by network node 114, may be adjusted over time. For example, the above information may be collected repeatedly and the parameters may be adjusted accordingly (using hysteresis and / or slow filtering as needed). In this way, the transmit power of the access terminals in the system may be controlled to match the current interference conditions in the system. For example, the maximum power parameter may be reduced if interference increases at a given node (eg, as determined by CQI reporting). In a simple case, the maximum _i is set to be equal to the minimum _i for each access point _i. In this case, network node 114 attempts to set these values to provide the same (or substantially the same) average CQI in each cell, which is each access terminal from each access point_i. It may be realized by using the Ec_i and j / Io measurements of j.

Next, with reference to FIGS. 7 and 8, the operation relating to the use of a method of varying the reception attenuation (such as uplink attenuation) over time to reduce interference will be described in more detail. In some embodiments, the scheme comprises defining a receive attenuation profile, such as profile 802, shown in FIG. 8, which defines different attenuation levels over time. Such profiles may take various forms and be defined in different ways. For example, in some cases, a profile may consist of a set of values that define reception attenuation at different time points. In some cases, the profile may be defined by an expression (eg, a sinusoidal waveform). As shown in FIG. 8, the profile may have a maximum value (MAX), a minimum value (MIN), and a period 804 defined.

In some embodiments, receive attenuation-based partial reuse may be achieved utilizing a receive attenuation profile, as described in more detail below. For example, neighboring access points may use the same profile (or similar profile) based on different phases of this profile. For example, the first access point receives according to the profile shown in FIG. 8, and the second access point receives using the same profile shifted 180 degrees. Therefore, when the first access point is receiving with the maximum attenuation, the second access point may be receiving with the minimum attenuation.

As represented by block 702 in FIG. 7, network node 114 (such as profile component 342 of interference controller 320) defines receive attenuation profile information used for radio reception (via uplinks, etc.). This information may include parameters such as reception attenuation profile, initial minimum and maximum values, and initial period value.

In some cases, one or more of these parameters may be pre-determined or randomly determined. However, these parameters are usually chosen to more effectively reduce interference between nodes in the system. The determination of this information is, for example, one or more measurement reports from one or more access terminals, one or more reports from one or more access points regarding CQI reported by one or more related access terminals, active access terminals. It can be based on various criteria such as the number of, and the average uplink traffic at each access point (eg, within each cell).

To give a specific example, the definition of receive attenuation profile parameters is how access points are arranged in the system (eg, total number of access points, density of access points within a given area, relative access points). It can be based on proximity, etc.). Here, if there are many nodes that are close to each other, the parameters may be defined so that neighboring nodes are less likely to receive at the same time with a high attenuation level. For example, the receive attenuation profile may be formed such that a given access point may receive with maximum or near maximum attenuation over a relatively short period of time. In this way, the receive attenuation profile provides proper isolation when a large number of phase values (60 degrees, 120 degrees, etc.) are used in connection with the receive attenuation profile by various nodes in the system. May be good. Conversely, if there are only a few nodes in the system, the parameters may be defined to increase communication performance (eg, throughput). For example, the receive attenuation profile may be formed such that a given access point may receive at maximum or near maximum attenuation level over an extended period of time.

Also, different levels of isolation between neighboring access points (eg, cells) may be achieved by adjusting the magnitude of the minimum and maximum parameters. For example, if the MAX / MIN ratio is higher, better separation is achieved at the expense of a longer time for the access terminal to receive at a lower attenuation level.

Receive attenuation profile parameters may be defined based on the traffic processed by each access point (eg, traffic load, traffic type, traffic quality requirements). For example, one type of traffic may be more susceptible to interference than another type of traffic. In such cases, parameters that provide higher isolation (eg, receive attenuation profile or MAX / MIN) may be used (eg, as described above). In addition, some traffic may have more stringent throughput requirements (although less sensitive to interference), thus providing more transmission at higher attenuation levels (eg, as described above). A receive attenuation profile that allows it may be used.

In some cases, network node 114 has a receive attenuation profile based on receive interference related information (eg, feedback from one or more access points and / or access terminals in the system, as described above in connection with FIG. 2). Parameters may be defined. For example, the number of access points contacted by a given access terminal and the relative proximity of the access points to the access terminal may be determined based on the measurement report received from the access terminal. In this way, the network node 114 may determine if transmission in a given cell (eg, a cell associated with a restricted access point) interferes with neighboring cells and adjust the attenuation profile parameters accordingly. Network node 114 may also define parameters based on interference information received from one or more access points (eg, as discussed in FIG. 2).

Depending on the implementation, the periodic parameter may be between the delay sensitivity of the application data (eg VoIP) and the filtering / delay of the downlink control communication path (eg CQI / DRC, ACK communication path, etc.) as described above. It may be defined based on trade-offs.

In some cases, as represented by block 704, network node 114 may specify a particular phase offset value and / or other parameters described above to be used by a particular access point. For example, network node 114 may determine the amount of interference a given access point receives when using different phase offsets. In this case, the phase offset associated with the lowest interference at this access point may be assigned to this access point.

The network node 114 may also specify the phase offset values of neighboring nodes so as to reduce interference between the nodes. To give a specific example, the network node 114 may determine that the uplink transmission by the access terminal 112 may interfere with the reception at the access point 104. This may be determined, for example, on the basis of uplink interference related information that may be acquired by network node 114 as discussed herein. Network node 114 may then specify different (eg, 180 degree out of phase) phase offset values for access points 104 and 106.

As represented by block 706, network node 114 then sends the attenuation profile information it defines to one or more access points. Here, the network node 114 may send a node-specific designation to each access point, or may send a common designation to all access points in the set of access points.

As represented by blocks 708 and 710, the access point 104 (eg, profile component 344 of the interference controller 322) determines the receive attenuation profile parameters it uses for uplink communication. If the network node 114 specifies all the receive attenuation profile parameters used by the access point 104, the access point 104 may simply use these parameters. In some cases, the access point 104 may randomly select parameters (such as phase offset).

If all parameters are not specified by network nodes 114 or are randomly selected, the access point 104 may decide which parameters to use based on appropriate criteria. In a typical case, the access point performs a tracking algorithm to dynamically determine the phase offset value that the access point 104 uses in conjunction with the receive attenuation profile, minimum, maximum, and periodic parameters received from network node 114. You may decide.

In some cases, the access point 104 may choose the phase offset value associated with the lowest interference. In this case, the access point 104 may determine which phase offset value to use as in the manner described above. For example, in block 708, the access point 104 may receive information (eg, a measurement report) from the access terminal 110 and / or the access point 104 may monitor the link to determine interference on the link. .. As an example of the latter case, the access point 104 may monitor interference (load) from outside the cell on the uplink when it is idle. In this way, the access point 104 may select the phase offset value that gives the minimum out-of-cell interference in the block 710.

In some cases, the access point 104 may work with one or more other access points to determine the phase offset value. For example, access point 104 and access point 106 may negotiate to use different (eg, out-of-phase) phase offset values. In such a case, the operation of the block 708 may not be performed.

As represented by block 712, the access point receives on the uplink based on the current receive attenuation profile (eg, by applying an attenuation profile to the received signal). Thus, reception attenuation may fluctuate over time in ways that may reduce interference with neighboring nodes.

The reception attenuation profile parameters described above (eg, maximum, minimum, and periodic parameters defined by network node 114) may be adjusted over time. For example, the above information may be collected repeatedly and the parameters may be adjusted accordingly (eg, using hysteresis and / or slow filtering as needed). In this way, the reception attenuation of the access terminal in the system may be controlled to match the current interference conditions in the system. For example, the attenuation (such as maximum attenuation) may increase as the received signal power level at one or more access points increases. In a simple case, the maximum _i is set to be equal to the minimum _i for each access point _i and is controlled in the same way as described above.

Next, with reference to FIGS. 9 and 10, the operation relating to the use of the partial reuse method using selective transmission (puncturing, etc.) on the uplink or downlink will be described in more detail. As mentioned above, the system can transmit between one or more defined time slots, which in various implementations are frames, subframes, slots, transmission time intervals (TTI"". ), HARQ interlace, etc., or may be referred to by these names.

In some embodiments, the partial reuse scheme may include configuring neighboring nodes (eg, access points and / or access terminals) to refrain from transmitting during part of one or more transmission time slots. .. For example, the first access point transmits during the first part of the time slot (eg, part or all of the subframe), and the second access point is the second part of the time slot (eg, eg). Transmit during another part of this subframe or a completely different subframe). As a result, the interference that would normally occur between nodes may be reduced.

In some embodiments, determining whether a node refrains from transmitting during a given portion of a time slot may include determining how much interference exists in different parts of this time slot. For example, a node may refrain from transmitting in parts of the time slot associated with higher interference.

First referring to FIG. 9, as represented by block 902, the network node 114 (eg, the time slot control component 346 of the interference controller 320) or some other suitable entity has a given transmit time slot or transmit time slot. The set of may determine how different nodes should be split into parts to selectively refrain from transmitting during one or more of these time slot parts. This may include, for example, determining parameters such as the structure of each time slot portion, the number of time slot portions, the size of each time slot portion, and the location of each time slot portion. In this case, it should be understood that a given time slot portion may be defined to include subordinate portions that are not temporally contiguous, or may be defined as a single contiguous period. In some cases, these time slot parameters may be predefined in the system.

Depending on the aspect, the parameters of the time slot portion may be defined to reduce interference in the system. To this end, the time slot portion is based on how each node is arranged in the system (eg, total number of access points, density of access points within a given area, relative proximity of access points, etc.). It may be defined based on. Here, if a large number of nodes are located in a given area, more time slot portions (and in some cases smaller portions, etc.) are defined and / or more intervals per time slot portion. Can be provided. In this way, it is less likely that neighboring nodes will use the same timeslot portion (or interference with neighboring timeslot portions), thereby allowing any node that potentially interferes with a certain timeslot. Alternatively, it may be configured so that transmission does not occur during most of the set of time slots. Conversely, if the system has only a small number of nodes, a smaller number of time slot parts (and in some cases, smaller and larger parts) are defined to improve communication performance (eg, throughput). May be good.

The time slot portion may also be defined based on the traffic processed by each access point (eg, traffic volume, traffic type, traffic quality requirements). For example, one type of traffic may be more susceptible to interference than another type of traffic. In such cases, more time slot portions may be defined and / or more intervals may be provided for the time slot portion minutes. In addition, some traffic may have more stringent throughput requirements (although less sensitive to interference), so a larger time slot portion may be defined.

The time slot portion may also be defined based on interference in the system. For example, if the interference value is high in the system, more time slot portions may be defined and / or more intervals may be provided for the time slot portion minutes.

Therefore, the operation of block 902 can be based on interference-related feedback from one or more access points and / or access terminals in the system (eg, as described above). For example, the measurement report of the access terminal and / or the report from the access node may be used to determine the degree to which the nodes in the system interfere with each other.

In some cases, as represented by block 904, network node 114 may specify a particular time slot portion used by a particular node. In some cases, time slot portions may be randomly assigned. However, usually the time slot portion may be chosen to reduce interference between nodes in the system. Depending on the aspect, determining which time slot portion a given node uses may be similar to the operation of block 902 described above. For example, network node 114 may determine the amount of interference associated with each time slot portion.

On the downlink, the access point may first be configured to use the first time slot portion. Interference associated with the use of this time slot portion may then be determined (eg, based on CQI reports collected over a period of time). The access point may then be configured to use the second time slot portion. Interference associated with the use of the second time slot portion may then be determined (eg, based on CQI reports collected over a period of time). The network controller can then allocate the time slot portion associated with the least interference to the access point.

On the uplink, the access terminal may initially be configured to use the first time slot portion. The interference associated with the use of this time slot portion is, for example, the transmit power used when transmitting over the uplink over a period of time (eg, automatically set by a power control command from the associated access point). It may be determined indirectly based on the value. The access terminal may then be configured to use the second time slot portion. The interference associated with the use of the second time slot portion may then be determined (eg, as described above). The network node 114 can then allocate the time slot portion associated with the lowest interference (indicated by, for example, the lowest uplink transmit power) to this access terminal and its associated access points.

The network node 114 can also specify the time slot portion of a neighboring node to reduce interference between the nodes. To give a specific example, network node 114 may determine that downlink transmission by access point 106 may interfere with reception at the access terminal associated with access point 104. This may be determined, for example, on the basis of downlink interference related information that network node 114 may acquire as discussed herein. To mitigate such potential interference, network node 114 can allocate different time slot portions to access points 104 and 106.

As represented by block 906, network node 114 may determine the timing offset of one or more access points in order to synchronize the time slot timing of each access point. Such synchronization may be achieved using adjustments such as, for example, Tau-DPCH (DPCH relates to a dedicated physical communication path) or some other suitable synchronization method.

As represented by block 908, network node 114 then sends the timeslot subparameters it defines to one or more access points. For example, network node 114 may send node-specific specifications to each access point or may send common specifications to all access points in the set of access points. The network node 114 may also send one or more timing offset displays to the access point for use in synchronous operation.

Next, referring to FIG. 10, this flow diagram shows an operation that may be performed by the access point for the downlink operation or by the access terminal for the uplink operation. First, we will deal with the case of downlinks.

As represented by block 1002, access point 104 (eg, timeslot control component 348 of interference controller 322) determines which timeslot portion it uses for downlink communication. If the network node 114 specifies the time slot portions used by the access point 104, the access point 104 may simply use these time slot portions. In some cases, the access point 104 may randomly choose which time slot portion to use.

If the time slot portion is not specified by the network node 114 or is randomly selected, the access point 104 may decide which time slot portion to use based on appropriate criteria. In some embodiments, the access point 104 may select the time slot portion associated with the least interference. In this case, the access point 104, in block 904 (eg, by using different parts over different periods and monitoring the CQI or some other parameter in each period), which time slot part, similar to the method described above. You may decide whether to use it.

In some cases, the access point 104 may work with one or more other access points to determine which time slot portion to use. For example, access point 104 and access point 106 may negotiate to use different (eg, mutually exclusive) time slot portions.

As represented by block 1004, the access point 104 may determine a timing offset for use in downlink communication. For example, the access point 104 may continuously monitor the link over a period of time to roughly determine when neighboring nodes start and end sending it. In this way, the access point 104 may determine (estimate, etc.) the timing of the time slot portion of the neighboring node. The access point may then synchronize its downlink time slot timing portion with this time. In some embodiments, this may include defining Tau-DPCH parameters.

As represented by block 1006, the access point 104 sends a message (eg, including timing offset information) to the relevant access terminal to inform the access terminal which time slot portion should be used for the downlink. May be good. In this way, the access point 104 may schedule downlink transmission in the best available time slot portion (block 1008).

Next, looking at the uplink scenario, as represented by block 1002, the access terminal 104 (such as the interference controller 324) determines the time slot portion that it uses for uplink communication. If the network node 114 specifies the time slot portions to be used by the access terminal 110, the access terminal 110 may simply use these time slot portions. In some cases, the access terminal 110 may randomly select which time slot portion to use.

If the time slot portion is not specified by the network node 114 or is randomly selected, the access terminal 110 may determine which time slot portion to use based on appropriate criteria. Depending on the embodiment, the access terminal 110 may select a time slot portion associated with the lowest interference (such as the lowest transmit power). In this case, the access terminal 110 may determine in block 904 which time slot portion to use in the same manner as described above, or even if this is automatically performed by the power control operation of the access point 104. Good.

In some cases, the access point 104 may monitor uplink interference during a time slot partial test, such as a test to determine which time slot portion has the least interference. In such cases, the access point 104 may instruct the access terminal 110 to use a particular time slot portion between predetermined phases of the interference test. Alternatively, the access terminal 110 may inform the access point 104 which time slot portion is being used during the predetermined phase of the test.

In some cases, the access point 104 may work with one or more other access points to determine which uplink time slot portion to use. For example, access point 104 and access point 106 may negotiate to use different (eg, mutually exclusive) time slot portions. In such a case, the access point 104 may transfer this information to the access terminal 110.

As represented by block 1004, the access terminal 110 may determine a timing offset for use in uplink or downlink communication. For example, access terminal 110 may continuously monitor links over a period of time to roughly determine when neighboring nodes start and end their transmission. In this way, the access terminal 110 may determine (estimate, etc.) the timing of the time slot portion of the neighboring node. Alternatively, the access terminal 110 may receive timing offset information (eg, Tau-DPCH parameter) from the access point 104. In either case, the access terminal 110 may then synchronize its uplink time slot timing portion with this time.

As represented by block 1006, the access terminal 110 may send a message to the access point 104 to inform the access point 104 which time slot portion should be used for the uplink. In this way, the access terminal 110 may schedule uplink data transmission in the optimal available time slot portion (block 1008).

The above operation may be repeated in order to constantly provide the optimum time slot portion for each node in the system. In some cases, it may be determined not to transmit at a particular pilot bit time in order to provide a more accurate SNR estimate (eg to EV-DO). In some cases, it may be determined not to transmit between certain overhead channels in order to provide better isolation (eg to HSPA). In addition, the access terminal may be prepared for lower signal measurements that can be received from access points using the methods described above.

Next, with reference to FIGS. 11 and 12, the operation relating to the use of the partial reuse method using the spectrum mask on the uplink or downlink will be described in more detail. In some embodiments, such a scheme may include configuring neighboring nodes (eg, access points and / or access terminals) to use different spectral masks when transmitting. In this case, instead of utilizing all available frequency spectra with constant power, each node may utilize a spectrum mask to create a non-uniform power spectral density. For example, the first access point transmits using a spectral mask associated with the first set of spectral components (eg, the first subset of the assigned frequency spectrum), and the second access point is the second set. Transmit using another spectral mask associated with the spectral component of (eg, a second subset of the assigned frequency spectrum). As a result, possible interference between nodes may be reduced.

In some embodiments, the determination as to whether a node uses a given spectral mask may include determining how much interference it will suffer when different spectral masks are used. For example, the node may choose to use a spectral mask associated with lower interference. In this case, it should be understood that a given spectral mask may be defined to include spectral components whose frequencies are not contiguous, or may be defined as frequencies in a single contiguous range. The spectrum mask may also include a positive mask (eg, defining a frequency component that should be used) or consist of a negative mask (eg, defining a frequency component that should not be used). May be good.

First referring to FIG. 11, as represented by block 1102, network node 114 (eg, spectrum mask control component 350 of interference controller 320) has different spectral components of the frequency spectrum assigned to uplink or downlink transmission. Information indicating interference associated with may be received.

Therefore, the operation of block 1102 may be based on interference-related feedback from one or more access points and / or access terminals in the system (eg, as described above). For example, measurement reports from access terminals and / or reports from access nodes may be used to determine the extent to which nodes in the system interfere with each other when a given spectral mask is used.

In some cases, network node 114 may specify a particular spectral mask to be used by a particular node, as represented by block 1104. In some cases, spectral masks may be randomly assigned. However, usually spectral masks may be chosen to more effectively reduce interference between nodes in the system.

For example, in a downlink, the access point may first be configured to use a first spectral mask (such as a filter defined by a particular spectral characteristic) when transmitting. The spectrum mask may be, for example, limited to only the first half of the substantially allocated spectrum (eg, the spectrum mask has substantially sufficient power spectral density in half of the spectrum and the spectrum. The other half of the has a significantly reduced power spectral density). The interference associated with the use of this spectral mask may then be determined (eg, based on CQI reports collected over a period of time). The access point may then be configured to use a second spectral mask (eg, limited to a substantially second half of the allocated spectrum). The interference associated with the use of the second spectral mask may then be determined (eg, based on CQI reports collected over a period of time). Network node 114 may then assign the access point a spectral mask associated with the lowest interference.

On the uplink, the access terminal may first be configured to use a first spectral mask when transmitting. The interference associated with the use of this spectral mask may then be determined (eg, based on uplink interference measured by the associated access terminal, etc.). The access terminal is then configured to use a second spectral mask to determine the interference associated with the use of the second spectral mask. Network node 114 may then assign the access terminal a spectral mask associated with the lowest interference.

The network node 114 may also specify the spectral masks of neighboring nodes to reduce interference between the nodes. To give a specific example, network node 114 may determine that downlink transmission by access point 106 may interfere with reception at the access terminal associated with access point 104. This may be determined, for example, on the basis of downlink interference related information that network node 114 may acquire as discussed herein. To mitigate such potential interference, network node 114 may assign access points 104 and 106 different spectral masks.

As represented by block 1106, network node 114 then sends the spectral mask it identifies to the appropriate access point (one or more). In this case, the network node 114 may send a node-specific message to each access point, or may send a message common to all access points in the set of access points.

Next, with reference to FIG. 12, this flow diagram shows the operations that may be performed by the access point and associated access terminals for uplink and downlink operations. As represented by block 1202, access point 104 (eg, spectrum mask control component 352 of interference controller 322) determines the spectrum mask used for the uplink or downlink. If network node 114 specifies a spectrum mask to be used, access point 104 may simply use the specified spectrum mask. In some cases, the access point 104 may randomly choose which spectral mask to use.

If the spectrum mask is not specified by the network node 114 or is randomly selected, the access point 104 may decide which spectrum mask to use based on appropriate criteria. In some embodiments, the access point 104 may select the spectral mask associated with the lowest interference. For example, access point 104 described above in blocks 1102 and 1104 (eg, by using different spectral masks over different periods and monitoring CQI or some other interference-related parameter during each period). You may decide which spectral mask to use in the same way.

In some cases, the access point 104 may work with one or more other access points to determine which spectral mask to use. For example, access point 104 and access point 106 may negotiate to use different (eg, mutually exclusive) spectral masks.

As represented by block 1204, the access point 104 sends a message to the access terminal 110 to inform the access terminal 110 which spectrum mask is used for the uplink (or optionally downlink). In this way, the access point 104 may transmit on the downlink using the best available spectrum, and / or the access terminal 110 may use the best available spectrum on the uplink. May be transmitted (block 1206). In this case, the equalizer at the receiving node (eg, the access terminal on the downlink) may mitigate the effect of the spectrum mask (especially if there is no load from neighboring cells). In addition, in some cases this equalizer can be adaptive and may take into account the specific spectral mask used at the transmitting node (eg, access point on the downlink).

The above operation may be repeated so as to constantly provide the optimum spectral mask for each node in the system.

Next, with reference to FIGS. 13 and 14, the operation related to the use of the partial reuse method using the diffusion code (Walsh code, OVSF code, etc.) will be described. In some embodiments, such a scheme may include configuring neighboring nodes (such as access points) to use different spreading codes when transmitting. In this case, each node may utilize a subset of the spreading codes instead of utilizing all the codes in the assigned set of spreading codes. For example, the first access point transmits using the first set of spreading codes and the second access point transmits using the second set of spreading codes. As a result, the interference that would normally occur between nodes may be reduced.

Depending on the aspect, determining whether a node uses a given spreading code may include determining how much interference it receives when different spreading codes are used. For example, the node may choose to use the spread code associated with lower interference.

First referring to FIG. 13, as represented by block 1302, the network node 114 (eg, the spread code control component 354 of the interfering controller 320) has a different spread of the set of spread codes assigned to the downlink transmission. Information indicating interference associated with a subset of codes may be received.

Therefore, the operation of block 1302 may be based on interference-related feedback from one or more access points and / or access terminals in the system (eg, as described above). For example, measurement reports from access terminals and / or reports from access nodes may be used to determine the extent to which nodes in the system interfere with each other when a given spread code is used.

In some cases, as represented by block 1304, network node 114 may specify a particular spread code to be used by a particular node. In some cases, diffusion codes may be randomly assigned. However, in general, the spreading code may be chosen to more effectively reduce interference between nodes in the system.

For example, the access point may first be configured to use a first set of spreading codes when transmitting over the downlink. The interference associated with the use of this set of diffusion codes may then be determined (eg, based on CQI reports collected over a period of time). The access point is then configured to use a second set of spreading codes to determine the interference associated with the use of the second set of spreading codes. Network node 114 may then assign the access point a spreading code associated with the lowest interference.

The network node 114 can also specify the spreading code of neighboring nodes to reduce interference between the nodes. To give a specific example, the network node 114 may determine that the downlink transmission by the access point 104 may interfere with the reception at the access terminal associated with the access point 106. This may be determined, for example, on the basis of downlink interference related information that network node 114 may acquire as discussed herein. To mitigate such potential interference, network node 114 may assign access points 104 and 106 different spread codes.

As represented by block 1306, network node 114 then sends the spread code it identifies to the appropriate (one or more) access points. In this case, the network node 114 may send a node-specific message to each access point, or may send a message common to all access points in the set of access points.

Network node 114 may also send one or more other sets of spreading codes to (one or more) access points, as represented by block 1308. As discussed in more detail below, these sets may identify spread codes that are not used by a given access point and / or spread codes that are used by some other access point.

Then referring to FIG. 14, as represented by block 1402, the access point 104 (eg, the spread code control component 356 of the interference controller 322) determines the set of spread codes used for the downlink. If network node 114 specifies a set to be used, access point 104 may simply use the specified set. In some cases, the access point 104 may randomly choose which set of spreading codes to use.

If a set of spreading codes is not specified by network nodes 114 or is randomly selected, the access point 104 may decide which set to use based on appropriate criteria. In some embodiments, the access point 104 may select the set of spreading codes associated with the lowest interference. For example, access point 104 resembles the method described above in blocks 1302 and 1304 (eg, by using different spread codes over different periods and monitoring CQI or some other interference-related parameter during each period). You may decide which set to use for.

In some cases, the access point 104 may work with one or more other access points to determine which set of spreading codes to use. For example, access point 104 and access point 106 may negotiate to use different (eg, mutually exclusive) sets of spreading codes.

As represented by block 1404, access point 104 may optionally synchronize its timing with the timing of one or more other access points. Orthogonal communication paths between access points, for example, by achieving chip alignment with neighboring cells (such as cells associated with other restricted access points), using different spread codes at each access point. May be established. Such synchronization may be achieved, for example, using techniques such as those described above (eg, each access point may include GPS functionality).

As represented by block 1406, access point 104 may optionally determine the spreading code used by one or more other access points. Such information may be obtained, for example, from network node 114 or directly from other access nodes (via backhaul, etc.).

As represented by block 1408, the access point 104 sends a message to the access terminal 110 to inform the access terminal 110 which spreading code is used for the downlink. In addition, the access point 104 gives the access terminal 110 information to identify the spread code not used by the access point 104 and / or the spread code used by some other access point (such as a neighboring access point). You may send it.

As represented by block 1410, the access point 104 transmits on the downlink using the selected set of spreading codes. In addition, as represented by block 1412, the access terminal 110 uses the spread code information sent by the access point 104 to decode the information received over the downlink.

Depending on the implementation, the access terminal 110 may be configured to more efficiently decode the received information by utilizing the information about the spreading code that is not used by the access point 104. For example, the signal processor 366 (eg, with interference elimination capability) has these other spread codes encoded from the received information using these other spread codes (eg, access point 106). ) May be used to eliminate any interference caused by the signal received from. In this case, the original received information is manipulated to provide decoding bits using these other spreading codes. A signal is then generated from the decoding bits and this signal is subtracted from the original received information. The resulting signal is then manipulated to provide an output signal using the spread code sent by the access point 104. Advantageously, by utilizing such an interference control technique, a relatively high level of interference elimination may be achieved even when the access point 104 and the access terminal 110 are not time synchronized.

The above operation may be repeated so as to constantly provide the optimum spreading code for each node in the system.

Next, with reference to FIGS. 15 and 16, the operation related to the use of the power control-related method for reducing interference will be described. In particular, these actions are performed by the access terminal in order to mitigate any interference that may occur on the uplink at an unrelated access point (eg, operating on the same carrier frequency as the adjacent carrier frequency). It relates to controlling transmission power.

As represented by block 1502, a node (eg, network node 114 or access point 104) may be used to determine how to control the uplink transmit power of the access terminal 110. Receive a signal. In various scenarios, the signal may be received from a network node 114, an access point 104, another access point (eg, access point 106), or an associated access terminal (eg, access point 110). Such information may be received in various ways (eg, via backhaul, over the air, etc.).

In some embodiments, these received signals may provide an indication of interference at a nearby access point (eg, access point 106). For example, as discussed herein, the access terminal associated with the access point 104 may generate measurement reports and send these reports to network node 114 via the access point 104.

In addition, the access point in the system may generate a load display (eg, a busy bit or a relative allowed communication path) and send this information to the associated access terminal over the downlink. Thus, the access point 104 may monitor the downlink to obtain this information, or may receive this information via the downlink from its associated access terminal.

In some cases, the interference information may be received from the network node 114 or from the access point 106 via the backhaul. For example, the access point 106 may report its load (interference, etc.) information to the network node 114. Network node 114 may then distribute this information to other access points in the system. In addition, each access point in the system may communicate directly with each other to inform each other of their individual load conditions.

As represented by block 1504, the transmission power display of the access terminal 110 is defined based on the above parameters. This display may relate, for example, to a maximum allowable power value, an instantaneous power value, or a traffic-to-pilot (T2P) display.

In some embodiments, the maximum transmit power value of the access terminal 110 is defined by estimating the interference that the access terminal 110 may induce at the access point 106. This interference may be estimated based on, for example, propagation loss information derived from the measurement report received from the access terminal 110. For example, the access terminal 110 may determine the propagation loss to the access point 106 in the propagation loss to the access point 104. Based on this information, the access point 104 may determine the power (eg, the amount of interference) induced at the access point 106 based on the signal strength of the signal received by the access point 104 from the access terminal 110. Therefore, the access point 104 may determine the maximum allowable transmission power at the access terminal 110 based on the measured value (for example, the maximum transmission power may be reduced by a certain amount).

Depending on the embodiment, an instantaneous power value may be generated to control the current transmission power of the access terminal. For example, if the amount of induced interference is greater than or equal to a threshold, the access terminal 110 may be instructed to reduce its transmit power (eg, by a certain amount or to a specified value). Good.

In some cases, the power control operation may be based on one or more parameters. For example, when the access point 104 receives a busy bit from the access point 106, the access point 104 uses the information from the measurement report to determine if interference at the access point 106 is caused by the access terminal 110. May be good.

Next, referring to FIG. 16, depending on the implementation, the transmission power display generated by block 1504 may be related to the maximum uplink T2P. Further, in some cases, this value may be defined as a function of the downlink SINR. Waveform 1602 in FIG. 16 shows an example of a function that associates a downlink SINR with an uplink T2P. In this case, the application of uplink T2P may be reduced as the downlink SINR decreases. In this way, uplink interference from access terminals on unbalanced links may be limited. As shown in the example of FIG. 16, the access terminal may have a minimum T2P value of 1604 defined such that a certain amount of minimum weight is guaranteed. In addition, a maximum T2P value of 1606 may also be defined. Depending on the embodiment, the uplink T2P assigned to each access terminal may be limited by the minimum power margin of each access terminal or a function based on the downlink SINR (as shown in FIG. 16). Depending on the implementation (3GPP, etc.), the above function may be provided by the uplink scheduler at the access point that accesses the CQI feedback from the access terminal.

Returning to FIG. 15, as shown in block 1506, depending on the implementation, the rise-over-thermal (RoT) threshold for the access point exceeds the normal value for load control. May be increased. For example, in some cases, the RoT threshold may not be limited. In some cases, the RoT threshold may be raised to a value limited only by the saturation level at the uplink link budget or access point. For example, the upper threshold RoT may be increased at the access point 104 to a predetermined value that allows each associated access terminal to operate at the highest T2P level allowed by its power margin.

By allowing such an increase in the RoT threshold, the access point may control its total received signal strength. This may be advantageous in situations where the access point is receiving a high level of interference (eg, from an adjacent access terminal). However, if there is no limit to the RoT threshold, access terminals in neighboring cells may fall into power competition to overcome interference from each other. For example, these access terminals may saturate at their maximum uplink transmit power (such as 23 dBm), resulting in significant interference at macro access points. To prevent such race conditions, the transmit power of the access terminal may be reduced as a result of the increase in the RoT threshold. In some cases, such race conditions may be avoided by utilizing the maximum uplink T2P control scheme (eg, as described above in connection with FIG. 16).

As represented by block 1508, the display of transmit power values (such as maximum power, instantaneous power, or T2P) calculated using one or more of the techniques described above is to control the transmit power of access terminal 110. It may be sent to the access terminal 110. Such messages may be sent directly or indirectly. As an example of the former, explicit signaling may be used to inform the access terminal 110 of the new maximum power value. As an example of the latter, the access point 104 may adjust the T2P and transfer the load display from the access point 106 (possibly after some modification) to the access terminal 110. The access terminal 110 may then use this parameter to determine the maximum power value.

Next, referring to FIG. 17, the signal attenuation factor may be adjusted to reduce interference depending on the implementation. Such parameters may include noise figure or attenuation. The amount of such padding or signal attenuation is the signal strength measured from other nodes (eg, as discussed herein), or a particular signal exchanged between access points (eg, indicating interference). It may be dynamically adjusted based on the transmitted message. In this way, the access point 104 may compensate for the interference induced by nearby access terminals.

As represented by block 1702, the access terminal 104 may receive power control related signals (eg, as described above). As represented by blocks 1704 and 1706, the access point 104 may determine if the received signal strength from the associated or unrelated access terminal is greater than or equal to the threshold level. If not above the threshold level, the access point 104 continues to monitor power control related signals. If above the threshold level, access point 104 adjusts the attenuation factor at block 1708. For example, in response to an increase in received signal strength, the access point 104 may increase its noise figure or receiver attenuation. As represented by block 1710, access points 104 reduce the uplink transmit power of these access terminals as a result of increased attenuation (eg, to overcome the noise figure or uplink attenuation imposed on access points 104). A transmit power control message may be sent to the associated access terminal due to the increase.

Depending on the aspect, the access point 104 may distinguish the signal received from the unrelated access terminal from the signal received from the related access terminal. In this way, the access terminal 104 may appropriately adjust the transmission power of the access terminal related thereto. For example, different adjustments may be made in response to signals from related and unrelated access terminals (eg, depending on whether there is only one associated access terminal).

In another embodiment, decoupling may be performed by an access point for access terminals that are not serviced by this access point, or for access terminals that are not part of the active set of access points. Good. To this end, a scrambled code (in W-CDMA or HSPA) or a user long code (in 1xEV-DO) among all access points (which receive scrambled codes from all access terminals). ) May be shared. The access point then decodes the individual access terminal information and removes the interference associated with the individual access terminal.

In some embodiments, the teachings herein are for large service areas (eg, wide area cellular networks such as 3G networks, commonly referred to as macro cell networks), and smaller service areas (eg, residential). It may be used in a network that includes a type or building type network environment). An access terminal (AT) is an access node that, in some places, provides a large service area when navigating such a network. It may be serviced by a node) (AN) and elsewhere by an access node that provides a smaller service area. In some embodiments, nodes in smaller service areas may be used to provide incremental capacity growth, in-building service areas, and various services (eg, for a more robust user experience). In the discussion herein, a node that provides a service area that covers a relatively large area is referred to as a macro node. A node that provides a service area that covers a relatively small area (for example, a house) is called a femto node. A node that provides a service area that is smaller than the macro area and larger than the femto area (for example, that provides a service area within a commercial building) is called a pico node.

A cell associated with a macro node, a femto node, or a pico node is referred to as a macro cell, a femto cell, or a pico cell, respectively. Depending on the implementation, each cell may be further associated with one or more sectors (eg, it may be split).

In various applications, other terms may also be used to refer to macronodes, femtonodes, or piconodes. For example, a macro node is configured as an access node, a base station, an access point, an ENodeB, a macro cell, or the like, and may be referred to by these names. The femto node is also configured as Home NodeB, Home eNodeB, access point base station, femtocell, and the like, and may be referred to by these names.

FIG. 18 shows a wireless communication system 1800 configured to support a large number of users, to which the teachings herein may be implemented. System 1800 provides communication to multiple cells 1802, for example macrocells 1802A to 1802G, and each cell is serviced by the corresponding access node 1804 (access node 1804A to 1804G, etc.). As shown in FIG. 18, access terminals 1806 (such as access terminals 1806A-1806L) may be placed at various locations throughout the system over time. Each access terminal 1806 has a forward link (FL"" at any moment, depending on, for example, whether the access terminal 1806 is active and whether the access terminal 1806 is in soft handoff. ) And / or reverse link (RL) may communicate with one or more access nodes 1804. The wireless communication system 1800 may provide services over a wide geographic area. For example, macrocells 1802A-1802G may cover several blocks in the vicinity.

FIG. 19 shows an exemplary communication system 1900 in which one or more femtonodes are located in a network environment. Specifically, System 1900 includes multiple femtonodes 1910 (such as femtonodes 1910A and 1910B) installed in a relatively small network environment (eg, in one or more user homes 1930). Each femtonode 1910 may be coupled to a WAN 1940 (such as the Internet) and mobile network operator core network 1950 via a DSL router, cable modem, wireless link, or other means of connection (not shown). As discussed below, each femtonode 1910 is configured to serve the associated access terminal 1920 (access terminal 1920A, etc.) and, optionally, the unrelated access terminal 1920 (access terminal 1920B, etc.). May be good. In other words, access to femtonode 1910 is serviced by a set of femtonodes 1910 (one or more) with a given access terminal 1920 (such as home) and non-designated femtonode 1910 (neighboring). Service provision by Femtonode 1910, etc.) may be restricted.

FIG. 20 shows an example of a service area map 2000 in which some tracking areas 2002 (or path selection areas or positioning areas) are defined, each containing some macro service areas 2004. In FIG. 20, each service area associated with tracking areas 2002A, 2002B, and 2002C is outlined with a wide line, and macro service area 2004 is represented by a hexagon. Tracking area 2002 also includes femto service area 2006. In this example, the femto service areas 2006 (such as the femto service area 2006C) are each illustrated inside a macro service area 2004 (eg, macro service area 2004B). However, it should be understood that femto service area 2006 may not be completely included within one macro service area 2004. In practice, a number of femto service areas 2006 may be defined along with a given tracking area 2002 or macro service area 2004. In addition, one or more pico service areas (not shown) may also be defined within the predetermined tracking area 2002 or macro service area 2004.

Returning to FIG. 19, the owner of the femtonode 1910 may subscribe to a mobile communication service, such as the 3G mobile communication service provided by the mobile operator core network 1950. In addition, the access terminal 1920 may be able to operate in both a macro environment and a smaller (eg, residential) network environment. In other words, depending on the current location of the access terminal 1920, the access terminal 1920 may be by the access node 1960 of the macrocellular mobile communication network 1950 or by a set of femtonodes 1910 (eg, a femtonode within the corresponding user residence 1930). The service may be provided by any one of 1910A and 1910B). For example, when a subscriber is out, the subscriber is serviced by a standard macro access node (eg, node 1960), and when at home, by a femto node (eg, node 1910A). Receive service. It should be understood that in this case the femtonode 1920 may be backwards compatible with the existing access terminal 1920.

The femtonode 1910 may be located on a single frequency or may be located on multiple frequencies. Depending on the individual configuration, this single frequency or one or more of the frequencies may overlap one or more frequencies used by the macro node (eg, node 1960).

In some embodiments, the access terminal 1920 may be configured to connect to a preferred femto node (eg, the home femto node of the access terminal 1920) whenever such a connection is possible. For example, the access terminal 1920 may only want to communicate with the home femto node 1910 whenever it is in the user's home 1930.

In some embodiments, the access terminal 1920 operates within the macro cellular network 1950, but if it is not on its most preferred network (eg, as defined in the preferred roaming list), the access terminal 1920 will be more Better System Reselection (BSR) may be used to continue exploring the most preferred network (eg, preferred femtonode 1910), which periodically sips the available systems. It may include scanning to determine if a better system is currently available and subsequently attempting to connect with such a preferred system. With respect to this acquisition entry, the access terminal 1920 may limit the search for a particular band and communication path. For example, the search for the most preferred system may be repeated periodically. When a preferred femto node 1910 is found, the access terminal 1920 selects the femto node 1910 to enter its service area.

Depending on the aspect, the femto node may be restricted. For example, a predetermined femto node may provide only a specific service on a specific access terminal. In a so-called restricted (or closed) association, a given access terminal is a macro-cell mobile communication network and a defined set of femtonodes (eg, femtonodes 1910 located within the corresponding user home 1930). Service may only be provided by. Depending on the implementation, the node may be restricted to not provide at least one of signaling, data access, registration, paging, or service for at least one node.

In some embodiments, a restricted femto node (also referred to as a Closed Subscriber Group Home Node B) is a femto node that provides services to a defined set of restricted access terminals. This set may be extended temporarily or permanently as needed. In some embodiments, a closed subscriber group (CSG) may be defined as a set of access nodes (eg, femtono) that share a common access control list of access terminals. A communication path in which all femto nodes (or all restricted femto nodes) in a certain area operate is called a femto communication path.

Therefore, various relationships may exist between a predetermined femto node and a predetermined access terminal. For example, when viewed from an access terminal, an open femtonode is a femtonode that has no restricted relevance. A restricted femtonode is a femtonode that is restricted in some way (eg, restricted for relevance and / or registration). A home femto node is a femto node that an access terminal is allowed to access and work with. A guest femto node is a femto node that is temporarily allowed to access and work with an access terminal. An irrelevant femtonode is a femtonode that an access terminal is not allowed to access or work with, except in an emergency (eg, 911 call).

From the perspective of the restricted femto node, the home access terminal is an access terminal that is allowed to access the restricted femto node. A guest access terminal is an access terminal that has a temporary access right to a restricted femto node. An irrelevant access terminal is an access terminal that is not allowed to access the restricted femto node except in an emergency such as a 911 call (eg, does not have a certificate or permission to register with the restricted femto node). Access terminal).

For convenience, the present disclosure shows various functions in the context of femtonodes. However, it should be understood that piconodes may also provide the same or similar functionality for a wider service area. For example, the pico node may be restricted, the home pico node may be defined for a given access terminal, and so on.

The wireless multiple access communication system may simultaneously support communication for multiple wireless access terminals. As described above, each terminal may communicate with one or more base stations by transmission over forward and reverse links. A forward link (or downlink) refers to a communication link from a base station to a terminal, and a reverse link (or uplink) refers to a communication link from a terminal to a base station. This communication link may be established via a single-input single-output system, a multi-input multi-output (MIMO) system, or some other type of system.

Multiple MIMO systems (N) for data transmission_T(1) transmitting antenna and multiple (N)_RUse) receiving antennas. N_TTransmitting antennas and N_RThe MIMO communication path formed by the individual receiving antennas is N, which is also called the spatial communication path._SDisassembled into individual independent communication paths, N_S min {N_T, N_R}. N_SEach independent communication path corresponds to one dimension. MIMO systems may achieve performance improvements (such as higher throughput and / or greater reliability) when the additional dimensions generated by multiple transmit and receive antennas are utilized.

MIMO systems may support Time Division Duplex (TDD) and Frequency Division Duplex (FDD). In the TDD system, forward and reverse link transmissions are placed on the same frequency domain so that the reciprocity principle allows the estimation of the forward link communication path from the reverse link communication path. This allows the access point to extract the transmit beam forming gain on the forward link when multiple antennas are available at the access point.

The teachings herein may be incorporated into a node (such as a device) that uses various components to communicate with at least one other node. FIG. 21 shows some exemplary components that can be used to facilitate communication between nodes. Specifically, FIG. 21 shows the wireless device 2110 (access point, etc.) and the wireless device 2150 (access terminal, etc.) of the MIMO system 2100. Instrument 2110 provides traffic data for several data streams from data source 2112 to transmit (TX) data processor 2114.

In some embodiments, each data stream is transmitted via an individual transmit antenna. The TX data processor 2114 formats, encodes, and interleaves the traffic data for each data stream based on the individual encoding scheme that each data stream chooses to provide the encoded data.

The coded data for each data stream may be multiplexed with the pilot data using OFDM techniques. Pilot data is a well-known data pattern that is usually processed in a well-known manner and may be used in the receiving system to estimate the communication path response. The multiplexed pilot and encoded data for each data stream is then subjected to the individual modulation scheme (BPSK, QSPK, M-PSK, M-QAM, etc.) selected for each data stream to provide the modulation symbol. Modulated based on (ie symbolic map is applied). The data transfer rate, coding and modulation for each data stream may be determined by instructions executed by processor 2130. The data memory 2132 may store program code, data, and other information used by other components of the processor 2130 or equipment 2110.

Modulation symbols for all data streams are then provided to the TX MIMO processor 2120, which may further process the modulation symbols (such as OFDM). The TX MIMO processor 2120 is then N via the 2122T._TN to multiple transmitters ("XCVR" 2122A)_TProvides a stream of modulation symbols. In some embodiments, the TX MIMO processor 2120 applies beam forming weights to the symbol of the data stream and to the antenna from which the symbol is transmitted.

Each transceiver 2122 receives an individual symbol stream, processes it to provide one or more analog signals, and then tunes (eg, amplifies, filters, upconverts) these analog signals to MIMO. A modulated signal suitable for transmission via a communication path is provided. Then N from transceivers 2122A ~ 2122T_TEach of the modulated signals is N_TIt is transmitted from two antennas 2124A to 2124T.

In equipment 2150, the transmitted modulated signal is N_RReceived by the individual antennas 2152A-2152R, the received signal from each antenna 2152 is provided to the individual transceivers (XCVR) 2154A-2154R. Each transceiver 2154 tunes (eg, filters, amplifies, downconverts) individual received signals, digitizes the tuned signals to provide samples, and further processes these samples for the corresponding "receive" symbol. Serve a stream.

The receive (RX) data processor 2160 is then N_RN from two transceivers 2154_RReceives a stream of received symbols and processes them based on individual receiver processing techniques, N_TProvides a stream of "detection" symbols. The RX data processor 2160 then demodulates, deinterleaves, and decodes each detection symbol stream to recover the traffic data in the data stream. The processing by the RX data processor 2160 is complementary to the processing performed by the TX MIMO processor 2120 and TX data processor 2114 in equipment 2110.

Processor 2170 periodically determines which precoding matrix to use (discussed below). Processor 2170 creates a reverse link message with a matrix exponential part and a floor number part. The data memory 2172 may store program code, data, and other information used by other components of the processor 2170 or device 2150.

The reverse link message can include various types of information about the communication link and / or the received data stream. The reverse link message is then processed by the TX data processor 2138, which also receives the traffic data of some data streams from the data source 2136, modulated by the modulator 2180, tuned by the transceivers 2154A-2154R, and sent back to equipment 2110. To.

In equipment 2110, the modulated signal from equipment 2150 was received by antenna 2124, tuned by transceiver 2122, demodulated by demodulator (DEMOD) 2140, processed by RX data processor 2142, and transmitted by equipment 2150. The reverse link message is retrieved. Processor 2130 then determines which precoding matrix to use to determine the beam formation weights, and then processes the retrieved message.

FIG. 21 also shows that the communication components may include one or more components that perform the interference control operations taught herein. For example, the interference control component 2190 works with other components of the processor 2130 and / or device 2110 to signal to and from another device (eg, device 2150) as taught herein. You may send / receive. Similarly, the interference control component 2192 may also work with other components of the processor 2170 and / or device 2150 to transmit / receive signals to and from another device (eg, device 2110). .. It should be understood that for each device 2110, 2150, more than one function of the aforementioned components may be provided by a single component. For example, a single processing component may provide the functionality of the interference control component 2190 and processor 2130, or a single processing component may provide the functionality of the interference control component 2192 and processor 2170. Good.

The teachings herein may be incorporated into various types of communication systems and / or system components. In some embodiments, the teachings herein are with multiple users by sharing available system resources (eg, by specifying one or more of bandwidth, transmit power, encoding, interleaving, etc.). It may be used in a multiple access system that can support the communication of. For example, the teachings herein are Code Division Multiple Access (CDMA) systems, Multiple-Carrier CDMA (MCCDMA) systems, Wideband CDMA (Wideband CDMA) (Wideband CDMA). W-CDMA), High-Speed Packet Access ("HSPA", "HSPA +") systems, Time Division Multiple Access ("TDMA") systems, Frequency Division Multiple Access (Frequency) Division Multiple Access (FDMA) system, Single-Carrier FDMA (SC-FDMA) system, Orthogonal Frequency Division Multiple Access (OFDMA) system, or other multiple access. It may be applied to any one of the connection techniques or a combination thereof. Radio communication systems using the teachings herein may be designed to implement one or more standards such as IS-95, cdma2000, IS-856, W-CDMA, TDSCDMA, and other standards. CDMA networks may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, or some other technology. UTRA is W-CDMA and Low Chip Rate) (LCR) is included. cdma2000 technology covers IS-2000, IS-95 and IS-856 standards. The TDMA network may implement wireless technologies such as the Global System for Mobile Communications (GSM). The OFDMA network may implement wireless technologies such as Evolved UTRA (E-UTRA), IEEE802.11, IEEE802.16, IEEE802.20, Flash-OFDM®, and the like. UTRA, E-UTRA, and GSM are part of the Universal Mobile Telecommunication System (UMTS). The teachings herein refer to 3GPP Long Term Evolution (LTE) systems, Ultra-Mobile. It may be implemented in Broadband (UMB) systems, and other types of systems. LTE is a release of UMTS that uses E-UTRA. Although some aspects of the disclosure may be described using 3GPP terminology, the teachings herein are also described in 3GPP (Release 99, 5, 6, 7) technology as well as 3GPP2 (IxRTT, 1xEV-). It should be understood that it may also apply to DO Release O, Revised A, Revised B) technology and other technologies.

The teachings herein can be incorporated into various devices (such as nodes) (implemented or performed within various devices). Depending on the embodiment, the node (such as a wireless node) implemented according to the teachings of the present specification may include an access point or an access terminal.

For example, an access terminal comprises a user device, a subscriber station, a subscriber unit, a mobile station, a mobile, a mobile node, a remote station, a remote terminal, a user terminal, a user agent, a user device, or some other term. Can be implemented as, or referred to by these names. Depending on the implementation, the access terminal may be a cellular telephone, a cordless telephone, a session initiation protocol (SIP) telephone, a wireless local loop (WLL) station, or a personal digital assistant. It may be equipped with a digital assistant (PDA), a handheld device with wireless connectivity, or any other suitable processing device connected to the wireless modem. Therefore, one or more aspects taught herein include telephones (such as cellular phones and smartphones), computers (such as laptops), portable communication devices, and portable computing devices (PDAs (personal data). (Assistant) etc.), entertainment equipment (music equipment, video equipment, satellite radios, etc.), global positioning system equipment, or any other suitable equipment configured to communicate via wireless media. ..

Access points are NodeB, eNodeB, radio network controller (RNC), base station (BS), radio base station (RBS), base station. Base station controller (BSC), base transceiver station (BTS), transceiver function (TF), wireless transceiver, wireless router, basic service set (basic) It comprises a service set (BSS), an extended service set (ESS), or some other similar term, implemented as these, or may be referred to by these names.

Depending on the embodiment, the node (such as an access point) may include an access node for a communication system. Such an access node may provide a connection to, for example, a network (eg, a wide area network such as the Internet or a cellular network) via a wired or wireless communication link to the network. Therefore, the access node may allow another node (eg, an access terminal) to access the network or some other function. In addition, it should be understood that one or both of these nodes may be portable and, in some cases, relatively difficult to carry.

It should also be understood that wireless nodes can also transmit and / or receive information other than wirelessly (eg, via a wired connection). Thus, receivers and transmitters as discussed herein may include suitable communication interface components (such as electrical or optical interface components) for communicating over non-radio media.

The radio node may communicate based on any suitable radio communication technology or via one or more radio communication links that support it otherwise. For example, in some embodiments, the radio node may be associated with the network. Depending on the embodiment, the network may include a local area network or a wide area network. The wireless device supports one or more of the various wireless communication technologies, protocols, or standards (eg, CDMA, TDMA, OFDM, OFDMA, WiMAX, Wi-Fi, etc.) as discussed herein. Alternatively, it may be used differently. Similarly, the radio node may support one or more of a variety of corresponding modulation or multiplexing schemes, or may be used differently. Thus, a wireless node may include components (such as an air interface) suitable for establishing one or more wireless communication links using the above or other wireless communication techniques and communicating through them. For example, a radio node may include a radio transceiver having associated transmit and receive components that may include various components (such as signal generators and signal processors) that facilitate communication over the radio medium. ..

Each component shown herein may be implemented in a variety of ways. With reference to FIGS. 22-30, the devices 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, and 3000 are represented as a series of interrelated functional blocks. In some embodiments, the functionality of these blocks may be implemented as a processing system that includes one or more processor components. In some embodiments, the function of these blocks may be performed using, for example, at least a portion of one or more integrated circuits (such as an ASIC). As discussed herein, integrated circuits may include processors, software, other related components, or any combination thereof. Also, the function of these blocks may be performed in some other way as taught herein. Depending on the embodiment, one or more of the broken line blocks in FIGS. 22 to 23 are optional.

Devices 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, and 3000 may include one or more modules that may perform one or more of the above-mentioned functions in relation to various figures. .. In some embodiments, one or more components of the interference controller 320 or interference controller 322 may include, for example, HARQ interlacing means 2202, profile specifying means 2302, phase offset means 2402, identification means 2502, spectrum masking means 2602, diffusion coding means 2702, Functions related to processing means 2802, transmission power means 2902, attenuation factor means 3004, and the like may be provided. Depending on the embodiment, the communication controller 326 or the communication controller 328 may provide, for example, a function relating to means 2204, 2304, 2404, 2504, 2604, 2704, or 2904. Depending on the embodiment, the timing controller 332 or the timing controller 334 may provide functions related to, for example, timing means 2206, 2506, or 2706. Depending on the aspect, the communication controller 330 may provide functions related to, for example, the receiving means 2802. Depending on the embodiment, the signal processor 366 may provide functions related to, for example, processing means 2804. Depending on the embodiment, the transceiver 302 or the transceiver 304 may provide functions related to, for example, the signal determining means 3002.

When referring to elements herein using designations such as "first," "second," etc., it should be understood that this generally does not limit the quantity or order of these elements. Is. Instead, these designations are used herein as a convenient way to distinguish between two or more elements, or instances of an element. Thus, references to the first and second elements mean that only two elements can be used there, but the first element must somehow precede the second element. It does not mean that it must be done. Also, unless otherwise specified, the set of elements may include one or more elements.

Those skilled in the art should understand that information and signals may be represented using any of a wide variety of techniques and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description are voltages, currents, electromagnetic waves, magnetic or magnetic particles, light fields or light particles, or any of these. It may be represented by any combination.

In addition, the various exemplary logic blocks, modules, processors, means, circuits, and algorithm steps presented in connection with the embodiments disclosed herein are all electronic hardware (source coding or some other technique. Various forms of incorporating instructions (referred to herein as "software" or "software modules" for convenience) as digital implementations, analog implementations, or a combination of both) that may be designed using. Those skilled in the art should also understand that it may be implemented as a program or design code, or as a combination of both. To articulate this hardware-software compatibility, various exemplary components, blocks, modules, circuits, and steps are generally described above in terms of their functionality. Whether such a function is implemented as hardware or software depends on the design constraints imposed on individual applications and the entire system. Those skilled in the art may perform the aforementioned functions in various ways for each individual application, but such implementation decisions should be construed as deviating from the scope of this disclosure. is not it.

The various exemplary logical blocks, modules, and circuits shown herein in connection with aspects of disclosure are such as within an integrated circuit (IC), access terminal, or access point, or these. May be carried out by. ICs are general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASIC), and field programmable gate arrays (FPGAs). ) Or other programmable logic device) (PLD), discrete gate or transistor logic, discrete hardware components, electrical components, optical components, mechanical components, or these designed to perform the functions described herein. It can be equipped with any combination and can execute code or instructions located inside the IC, outside the IC, or both. The general purpose processor can be a microprocessor, but as an alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented as a combination of computing devices, such as a combination of DSP and microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. Good.

It is understood that any particular order or hierarchy of steps in the disclosure process is an example of an exemplary approach. It is understood that the particular order or hierarchy of steps in each process may be reorganized based on design choices without going beyond the scope of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to limit themselves to the particular order or hierarchy presented.

Each of the above functions may be performed as hardware, software, firmware, or any combination thereof. When implemented as software, each function may be stored or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include both computer storage media and communication media, including any medium that facilitates the transfer of computer programs from one location to another. The storage medium can be any available medium that may be accessed by a computer. Such computer-readable media include, but are not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or the desired program code. It may include any other medium that can be used to carry or store as instructions or data structures and may be accessed by a computer. Also, any connection is, of course, called a computer-readable medium. For example, the software may use coaxial cable, fiber optic cable, stranded wire, digital subscriber line (DSL), or wireless technology such as infrared, radio, or microwave to create a website, server, or When transmitted from other remote sources, wireless technologies such as coaxial cable, fiber optic cable, stranded, DSL, or infrared, radio, microwave are included in the definition of medium. As used herein, "disk" and "disc" are compact discs (CDs), laser discs, optical discs, and digital versatile discs. Includes disc) (DVD), floppy (registered trademark) discs and Blu-ray discs, where a disk typically reproduces data magnetically and a disc uses a laser to optically reproduce data. Also, a combination of the above should be included within the scope of a computer-readable medium. In summary, it should be understood that computer-readable media may be implemented as any suitable computer program product.

The above description of aspects of the disclosure is provided to allow one of ordinary skill in the art to create or use the present disclosure. Various modifications to these embodiments should be readily apparent to those of skill in the art, and the general principles defined herein may apply to other embodiments without departing from the scope of the present disclosure. Good. Therefore, the present disclosure should not be limited to the aspects presented herein, and the present invention should be tolerated to the maximum extent consistent with the principles and novel features disclosed herein. is there.