Signaling message transmission in a wireless communication network

Signal transmission in wireless communication network

This patent application requests the right of priority to the U.S. Provisional Application No. 61/040,489 filed on March 28, 2008 with the title of "ORTHOGONAL RESOURCE UTILIZATION MESSAGE (RUM) DESIGN", which has been assigned to this application The assignee of is incorporated into this application by reference.

Broadly speaking, the present invention relates to communication. Specifically, the present invention relates to a technology for sending and receiving signaling messages in a wireless communication network.

Nowadays, wireless communication networks have been widely deployed to provide various communication services, such as voice, video, packet data, messaging, broadcasting, and so on. These wireless networks may be multiple access networks, which can support multiple users by sharing available network resources. Examples of such multiple access networks include: code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) network and single carrier FDMA (SC-FDMA) network.

The wireless communication network may include multiple base stations, which can support communication of multiple user equipment (UE). The base station can send signaling messages for various purposes to the UE. The UE can also send signaling messages for various purposes to the base station. These signaling messages can be used to support the communication between the base station and the UE. People expect to be able to send signalling messages efficiently and reliably.

This article describes the technology for sending signaling messages in wireless communication networks. In one aspect, the signaling message can be sent by mapping the signaling message to at least one specific subcarrier in the set of subcarriers reserved for sending the signaling message. The signaling message can have one of multiple possible values. The signaling message can be sent on at least one specific sub-carrier selected from the set of sub-carriers based on the message value. In one design, the signaling message may be an interference reduction request requesting at least one interfering station to reduce interference to the transmitter station. The transmitter station can select at least one sub-carrier in the set of sub-carriers based on the signaling message. The transmitter station can transmit a signal (for example, a phase continuous signal) on each selected sub-carrier in multiple symbol periods to transmit a signaling message. The receiver station can perform the reverse processing to detect the signalling message.

In another aspect, the request for reducing interference may be sent based on one of all orthogonal resources (for example, code, time, frequency, and/or other resources) available for sending the request for reducing interference. In a design solution, the first station may generate an interference reduction request to request at least one interfering station to reduce interference to the first station. The first station can extend the interference reduction request into one resource segment according to the orthogonal sequence. The resource segment may cover multiple sub-carriers in multiple symbol periods. In an orthogonal design scheme, M possible values of the interference reduction request can be mapped to M orthogonal sequences (for example, Walsh sequences). The first station may select the orthogonal sequence according to the interference reduction request, and map the selected orthogonal sequence to the resource segment. In another orthogonal design solution, the first station can process (for example, encode and modulate) the interference reduction request to obtain modulation symbols, and expand each modulation symbol to obtain a corresponding data sequence. The first station can transmit each data sequence through a set of sub-carriers in a symbol period to achieve frequency extension. For these two orthogonal design schemes, the first station can generate a signal including a request for reducing interference, where the request for reducing interference is extended to the resource segment, and the first station can send the generated signal to at least one interfering station. The interfering station can perform the opposite process to detect the request to reduce interference.

The various aspects and features of the present invention will be described in further detail below.

The technology described in this application can be used in various wireless communication networks, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms "network" and "system" are often used interchangeably. CDMA networks can implement wireless technologies such as Universal Terrestrial Radio Access (UTRA), CDMA 2000, and so on. UTRA includes wideband CDMA (WCDMA) and other variants of CDMA. CDMA 2000 covers IS-2000, IS-95 and IS-856 standards. TDMA networks can implement wireless technologies such as the Global System for Mobile Communications (GSM). OFDMA network can realize such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, flash OFDM<img file="TW201014287A_D0001.tif" />And so on wireless technology. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) and LTE Advanced (LTE-A) are new releases of UMTS using E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CDMA 2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The technologies described in this article can be used for the wireless networks and wireless technologies mentioned above as well as other wireless networks and wireless technologies.

FIG. 1 shows a wireless communication network 100, which includes a plurality of base stations 110 and other network entities. A base station is a station that communicates with a UE, and it can also be called a Node B, an evolved Node B (eNB), an access point, and so on. Each base station 110 can provide communication coverage for a specific geographic area. The term "cell service area" refers to the coverage area of a base station and/or the base station subsystem serving this coverage area.

The base station can provide communication coverage for the macro cell service area, pico cell service area, femto cell service area, and so on. The macro cell service area can cover a relatively large geographic area (for example, within a few kilometers), which can allow UEs with traffic subscriptions to access without restriction. The pico cell service area covers a relatively small geographic area, which can allow unrestricted access by UEs with traffic subscriptions. The femtocell service area covers a relatively small geographic area (for example, in a house), which may allow restricted access by UEs associated with the femtocell service area. The base station used in the macro cell service area can be referred to as a macro base station. The base station used in the pico cell service area can be called a pico base station. The base station used in the femto cell service area can be called a femto base station or a home base station.

In the example shown in FIG. 1, the base stations 110a, 110b, and 110c may be macro base stations for the macro cell service areas 102a, 102b, and 102c, respectively. The base station 110x may be a pico base station used in the pico cell service area 102x. The base station 110y may be a femto base station for the femto cell service area 102y. The pico cell service area and the femto cell service area may be located in the macro cell service area (for example, as shown in FIG. 1) and/or may overlap with the macro cell service area.

The wireless network 100 may also include a relay station, for example, a relay station 110z. A relay station (or repeater) is a station that receives the transmission of data and/or other information from the upstream station and sends the transmission of these data and/or other information to the downstream station. The network controller 130 may be coupled to a group of base stations, and coordinate and control these base stations. The network controller 130 may be a single network entity or a collection of network entities.

The UE 120 may be dispersed in the wireless network 100, and each UE may be stationary or mobile. The UE can also be referred to as a terminal, a mobile station, a subscriber unit, a station, and so on. The UE may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a wireless phone, a wireless local loop (WLL) station, and so on. The UE can communicate with the base station via the downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station. The UE can communicate with macro base stations, pico base stations, femto base stations, relay stations, and so on. In FIG. 1, the solid line with double arrows indicates the desired transmission between the UE and the serving base station, where the serving base station is a base station designated to serve the UE on the uplink and/or downlink. A dotted line with a double arrow indicates interference transmission between the UE and the base station.

The wireless network 100 may be a similar network including only macro base stations. The wireless network 100 may also be a heterogeneous network including different types of base stations (for example, a macro base station, a pico base station, a femto base station, a relay station, etc.). These different types of base stations may have different transmit power levels, different coverage areas, and have different interference effects in the wireless network 100. For example, a macro base station may have a high transmit power level (e.g., 20 watts), while a pico base station and a femto base station may have a lower transmit power level (e.g., 1 watt). The technology described in this application can be used for similar and heterogeneous networks.

The wireless network 100 may be a synchronous network or an asynchronous network. In a synchronous network, these base stations can have similar frame timing, and transmissions from different base stations can be aligned in time. In an asynchronous network, these base stations may have different frame timings, and transmissions from different base stations may not be aligned in time. The technology described in this application can be used for both synchronous and asynchronous networks.

The wireless network 100 may use Orthogonal Frequency Division Multiplexing (OFDM) and/or Single Carrier Frequency Division Multiplexing (SC-FDM). For example, the wireless network 100 may be an LTE network using OFDM on the downlink and SC-FDM on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (N_FFT) Sub-carrier, sub-carrier can also be called tone, frequency band and so on. The distance between adjacent sub-carriers can be fixed, and the total number of sub-carriers (N_FFT) Depends on the system bandwidth. For example, for a system bandwidth of 1.25, 2.5, 5, 10, or 20MHz, N_FFTCan be equal to 128, 256, 512, 1034, or 2048, respectively.

The UE can communicate with the serving base station in a scene with significant interference, where the scene with significant interference is characterized in that the interference power is higher than the expected signal power. On the downlink, the UE may experience high interference from one or more interfering base stations. On the uplink, the serving base station may be subject to high interference from one or more interfering UEs. The significant interference scenario may be caused by range extension. In this scenario, the UE is connected to a base station with lower path loss and lower geometry among multiple base stations detected by the UE. For example, when the UE 120x in FIG. 1 communicates with the pico base station 110x with lower path loss and lower geometric arrangement, the UE 120x may be subject to high interference from the macro base station 110b. This is desirable for reducing interference to the wireless network in order to achieve a given data rate for the UE. The significant interference scenario can also be caused by restricted associations. In this scenario, the UE cannot connect to a strong base station with restricted access, so that the UE is connected to a weaker base station with unrestricted access. For example, the UE 120y in FIG. 1 cannot connect to the femto base station 110y, but connects to the macro base station 110c. The UE 120y may receive high interference from the femto base station 110y, and may also cause high interference to the femto base station 110y.

In order to improve the performance of data transmission, interference mitigation can be used to mitigate (e.g., avoid or reduce) the interference on a given link. Interference mitigation can also be used to provide cell service area splitting gain. For example, a macro base station can reserve resources used by multiple pico base stations to serve different UEs at the same time. For interference mitigation, the interfering station can blank or reduce its transmit power, or the interfering station can beamsteer its transmission so that the desired transmission of the target station can achieve higher received signal quality . In the description of this application, the station may be a base station, UE, relay station, and so on. The received signal quality can be quantified by the signal to noise plus interference ratio (SINR) or some other metric.

FIG. 2 shows a design scheme of a downlink data transmission scheme 200 using interference mitigation. The serving base station has data sent to the UE, and the serving base station understands that the UE is experiencing high interference on the downlink. For example, the serving base station may receive pilot frequency measurement reports from the UE, and these reports may indicate and/or identify strong interfering base stations. The serving base station can send an interference mitigation trigger to the UE. The trigger can cause the UE to request the interfering base station to reduce interference on the downlink. The trigger may also transmit specific resources used to reduce interference on it, the priority of the request, and/or other information.

The UE can receive the interference mitigation trigger from the serving base station, and then can send the interference reduction request. The request to reduce interference can also be referred to as a resource utilization message (RUM). The UE may send the request to reduce interference as: (i) only a unicast message for the strong interfering base station, or (ii) a broadcast message for all neighboring base stations. The interference reduction request may request the interfering base station to reduce the interference on the designated resources, and the interference reduction request may also transmit the priority order of the request, the target interference level of the UE, and/or other information.

The interfering base station may receive a request to reduce interference from the UE, and then may agree or reject the request. If the request is approved, the interfering base station can adjust its transmit power and/or control its transmission in order to reduce the interference to the UE. In a design scheme, the interfering base station can determine the transmit power level that it will use on the designated resource according to various factors such as its buffer status, the priority of the request, the target interference level of the UE, etc.<i>P</i>_<i>d</i>. Subsequently, the interfering base station can be based on the power level<i>P</i>_<i>pdp</i>To send the power decision pilot frequency, where<i>P</i>_<i>pdp</i>Can be equal to<i>P</i>_<i>d</i>Or for<i>P</i>_<i>d</i>Zoomed version.

The UE can receive power decision pilot frequency from all interfering base stations and serving base stations. The UE may estimate the SINR of the designated resource according to the received pilot frequency, determine the channel quality indicator (CQI) information according to the estimated SINR, and send the CQI information to the serving base station.

The serving base station may receive CQI information from the UE, and schedule the UE for data transmission on the allocated resources, where the allocated resources may include all designated resources or a subset of designated resources. The serving base station can select a modulation and coding scheme (MCS) based on the CQI information, and can process data packets based on the selected MCS. The serving base station can generate downlink (DL) grant information (grant), which includes allocated resources, selected MCS, and so on. The serving base station can send downlink authorization information and packet transmission to the UE. The UE can receive downlink authorization information and packet transmission, and decode the received transmission according to the selected MCS. Subsequently, the UE may generate acknowledgment (ACK) information, which indicates whether the UE decoded the packet correctly or incorrectly, and the UE may send the ACK information to the serving base station.

FIG. 3 shows a design scheme of an uplink data transmission scheme 300 using interference mitigation. The UE has information to send to the serving base station, and the UE can send a resource request. The resource request can indicate the priority of the request, the amount of data to be sent by the UE, and so on. The serving base station can receive this resource request and send a transmission capability request to the UE, so as to request the UE's transmission capability on a specific resource. The serving base station may also send a request to reduce interference to request the interfering UE to reduce interference on specific resources. The serving base station may send the interference reduction request as: (i) a unicast message only for strongly interfering UEs, or (ii) a broadcast message for all interfering UEs.

The UE can receive transmission capability requests from the serving base station, and can also receive interference reduction requests from neighboring base stations. The UE determines the transmit power level that it can use on the designated resource according to the interference reduction request from the neighboring base station. The UE can transmit the transmit power level via the power decision pilot frequency.

The serving base station can receive the power decision pilot frequency from the UE and the interfering UE. The serving base station may estimate the SINR of the designated resource according to the received pilot frequency, and select the MCS for the UE according to the estimated SINR. The serving base station can generate and send uplink authorization information, which can include the selected MCS, the allocated resources, the transmit power level used for the allocated resources, and so on. The UE can receive the uplink authorization information, process the packet according to the selected MCS, and send the packet transmission on the allocated resources. The serving base station can receive the packet transmission from the UE, decode the received transmission, determine the ACK information according to the decoding result, and send the ACK information to the UE.

As shown in Figures 2 and 3, in order to support interference mitigation, various signaling messages can be sent on the downlink and uplink. Each type of signaling message can include any type of information. For example, the request to reduce interference may include some or all of the following information:

Resource Index-Identifies the resource on which less interference is requested;

Priority level-indicates the priority order of interference reduction requests;

Spatial feedback information-used for beam steering to deviate from the sender;

Transmitter Identifier (ID)-Identifies the sender of the interference reduction request.

The interference reduction request may also include different and/or other information.

This type of signaling message can be sent on the resources reserved for sending a specific type of signaling message (for example, a request to reduce interference). Resources can be reserved in various ways. In a design solution, the reserved resources may include frequency resources that are available at all times. This design scheme is especially suitable for asynchronous networks. In another design solution, the reserved resources may include specific time and frequency resources. This design scheme is more suitable for synchronous networks.

FIG. 4A shows a design scheme for reserving frequency resources for sending a specific type of signaling message (for example, a request to reduce interference). In this design, a set of consecutive sub-carriers can be reserved for sending signaling messages. Generally speaking, this group of subcarriers can be located anywhere in the system bandwidth. In a design solution, one or more protection sub-carriers can be used to protect/isolate reserved sub-carriers from non-reserved sub-carriers used to transmit data, etc. For example, as shown in FIG. 4A, a guard subcarrier can be used on each side of the reserved subcarrier. These protection sub-carriers can protect the signaling messages sent on the reserved sub-carriers from inter-carrier interference (ICI) caused by transmissions on the non-reserved sub-carriers, thereby improving the detection of signaling messages.

FIG. 4B shows another design scheme for reserving frequency resources for sending a specific type of signaling message (for example, a request to reduce interference). In this design solution, a set of subcarriers may be reserved for sending signaling messages, and the set of subcarriers may include two consecutive subsets of subcarriers. Each subset may include half of the reserved subcarriers. Generally speaking, a subset of sub-carriers can be located anywhere in the system bandwidth. In the design shown in Figure 4B, these two subsets are located at the two edges of the system bandwidth. In a design solution, as shown in FIG. 4B, one or more protection sub-carriers may be used to protect each subset of reserved sub-carriers from non-reserved sub-carriers.

4A and 4B show two exemplary design schemes for reserving frequency resources for sending specific types of signaling messages. Other methods can also be used to reserve time and/or frequency resources for sending signaling messages. For example, more than two sub-carrier subsets can be reserved for sending signaling messages.

In a design solution, different resources (for example, different subcarrier sets, different time-frequency resource blocks, etc.) can be reserved so that base stations with different power classes (classes) can send signaling messages (for example, reduce Interference request). In another design solution, different resources can be reserved to send signaling messages at different transmit power levels. The transmitter station can send the signaling message on a reserved sub-carrier set, where the reserved sub-carrier set is selected according to the power category of the transmitter station, the distance from the transmitter station to the receiver station, and so on.

In a design scheme, different resources can be reserved for sending specific types of signaling messages for different cell service areas. This design solution for each cell service area can avoid conflicts between the signaling messages from different cell service areas. In another design, the same resources can be reserved for all cell service areas that send specific types of signaling messages. This kind of global design can reduce the management burden of sending signaling messages. Generally speaking, some resources (e.g., sub-carrier set) can be reserved for sending signaling messages (e.g., request to reduce interference). Multiple transmitter stations can use the same resource (for example, the same reserved sub-carrier) to send the signaling message. In some cases, these transmitter stations can send the same message, and these messages can be overlapped at the receiver station in a single frequency network (SFN) manner.

The signaling messages in Figures 2 and 3 and other signaling messages used to support communication between the base station and the UE can be sent in various ways. This type of signaling message can be sent on the resources reserved for sending a specific type of signaling message (for example, a request to reduce interference). The following describes some exemplary design schemes for sending signaling messages.

In the first design solution, the signaling message (for example, a request to reduce interference) may be mapped to at least one specific subcarrier (for example, a specific subcarrier) for transmission. The signaling message can include all B information bits, of which<img file="TW201014287A_D0002.tif" />And it depends on the amount of information to be sent. The signaling message can have one of M possible values, where M=2^B. In one design, a set with M sub-carriers may be reserved for sending signaling messages, for example, as shown in FIG. 4A or 4B. Subsequently, the signaling message can be sent on one sub-carrier of the reserved M sub-carriers.

FIG. 5 shows a design scheme of the message transmission scheme 500 using sub-carrier mapping. A set of reserved M subcarriers with indexes 0 to M-1 can be used to send the signaling message. For example, a set of 8 secondary carriers can be used to send a 3-bit interference reduction request, a set of 16 secondary carriers can be used to send a 4-bit request, and so on. Each of the M possible values of the signaling message can be mapped to a different sub-carrier of the M sub-carriers. For example, the message values from 0 to M-1 can be mapped to subcarriers 0 to M-1, respectively. The signaling message can be mapped to a specific subcarrier in the reserved subcarrier set according to the message value. Subsequently, a signal is sent on the selected sub-carrier with an appropriate transmit power level (for example, full power) and an appropriate duration (for example, a predetermined number of symbol periods) to ensure reliable reception of the signaling message. No signal is sent on the M-1 remaining sub-carriers in the reserved sub-carrier set.

Generally speaking, any information of the signaling message can be distributed on different sub-carriers in the reserved set. In one design solution, the reserved M subcarriers can be associated with different priority orders of the signaling message. For example, eight sub-carriers can be used to support eight priority levels. Subsequently, the selected sub-carrier can be associated with the priority order of the signaling messages sent on that sub-carrier. In another design solution, different cell service areas or UE identities (IDs) may be scattered on different sub-carriers of the reserved sub-carrier set. Subsequently, the selected secondary carrier can be associated with the ID of the base station or UE that sent the signaling message. In another design solution, the combination of priority order and cell service area or UE ID can be spread on different subcarriers of the reserved subcarrier set. For example, the signaling message can include 3-bit cell service area or UE ID and 1-bit priority. The four bits of the signaling message can be used to select one of the 16 sub-carriers of the reserved set. It is also possible to map other combinations of information to different sub-carriers. You can also select more than one subcarrier based on the message value.

For the first design solution, the receiver station can detect the signaling message (for example, a request to reduce interference) as shown below. The receiver station can obtain time-domain samples of the received signal. In each symbol period, a fast Fourier transform (FFT) can be performed on the time domain samples for all N_FFTAll sub-carriers obtain frequency-domain reception symbols. The received power of each sub-carrier in the reserved set can be determined based on the symbols received on the sub-carrier. The received power of each sub-carrier can be compared with the power critical value to determine whether a signal is sent on the sub-carrier. For each subcarrier on which a signal is detected, the message value of the signaling message can be recovered according to the index of the subcarrier. In a design solution, the power critical value may be a static value, which may be determined based on computer simulation or empirical measurement to obtain good detection performance. In another design solution, the power critical value can be dynamically determined, for example, according to the received power of all reserved sub-carriers, the received power of all available sub-carriers, and so on.

The message transmission scheme 500 can be used for both synchronous and asynchronous networks. In one design, a phase-continuous signal can be sent on the sub-carrier selected for the signaling message. A phase-continuous signal is a signal with little or no phase discontinuity in consecutive symbol periods, which makes the start of the waveform (for example, sinusoidal) of a given symbol period a continuation of the waveform of the previous symbol period. The use of a continuous phase signal allows the receiver station to detect the signal on the selected sub-carrier with a smaller ICI even if its FFT window is not aligned with the symbol boundary timing of the transmitter station due to asynchronous operation. .

The message transmission scheme 500 can appropriately handle the conflict of signaling messages on the reserved subcarrier set. If multiple transmitter stations send signaling messages on different sub-carriers at the same time or almost the same time, the receiver station can detect the signaling messages from each transmitter station and respond to each signaling message . If multiple transmitter stations send signal messages on the same sub-carrier at the same time or almost the same time, then the receiver station receives repeated signal messages on that sub-carrier and responds to these repeated signal messages . Therefore, signaling messages can be sent in SFN networks in a manner similar to broadcast transmission.

In the second design solution, time and frequency extension can be used to send a request to reduce interference. In this design scheme, M orthogonal sequences can be defined, which can be Walsh sequences or some other extended sequences, these sequences have good correlation characteristics, and these sequences can be orthogonal or non-orthogonal to each other. Each orthogonal sequence may have a length of M and include M symbols. Each of the M possible values of the interference reduction request may be mapped to a different orthogonal sequence among the M orthogonal sequences. The request for reducing interference may be sent using one of M orthogonal sequences selected based on the value of the request for reducing interference.

Fig. 6 shows a design scheme of a message transmission scheme 600 using time and frequency extension. The request for reducing interference can be mapped to a specific orthogonal sequence of length M according to the message value. The selected orthogonal sequence may be sent on a resource segment covering N sub-carriers in T symbol periods. The resource segment includes M resource units, where M=NT. Each resource unit can cover one sub-carrier in one symbol period, and each resource unit can be used to transmit one symbol, and the symbol can be a real number or a complex value. The M symbols in the selected orthogonal sequence may be mapped to the M resource units in the resource segment in a predetermined order. For example, these M symbols can be mapped to: (i) all N sub-carriers of one symbol period at a time, as shown in FIG. 6; (ii) all T symbol periods of one sub-carrier at a time.

As shown in Figure 6, the resource segment can cover N sub-carriers in T symbol periods. In a design solution, a set of N subcarriers may be reserved for sending a request to reduce interference. If these N subcarriers are continuous, the detection performance can be improved. The resource segment can be formed on N subcarriers (starting at any symbol period) in the reserved subcarrier set. This design can be used for synchronous and asynchronous networks. In another design solution, a specific resource segment may be reserved for sending a request to reduce interference. This design scheme is more suitable for synchronous networks. The resource segment reserved for sending the request to reduce interference can also be defined according to other methods.

In one design solution, the preamble signal may be sent before the orthogonal sequence used to reduce the interference request. The preamble signal may be a specific sequence sent on N secondary carriers in one symbol period before the orthogonal sequence. The preamble signal can be used to detect the presence of a request to reduce interference.

For the second design solution, the receiver station can detect the interference reduction request as follows. First, the preamble signal (if sent) can be detected to determine that there is a request to reduce interference. Subsequently, M received symbols can be obtained from M resource units in the resource segment. Each of the M possible orthogonal sequences can be used to despread the M received symbols to obtain M despread symbols, and each orthogonal sequence corresponds to one despread symbol. The received power of each despread symbol can be compared with the power critical value, and if the received power exceeds the power critical value, the interference reduction request corresponding to the despread symbol is detected. In a design scheme, the power critical value can be a static value, which can be determined based on computer simulation or empirical measurement to obtain good detection performance. In another design solution, the power critical value can be dynamically determined, for example, based on the received power of the N sub-carriers in the reserved sub-carrier set when there is no request to reduce interference.

The message transmission scheme 600 may allow the use of larger transmission power to transmit the interference reduction request and the extension of the interference reduction request to multiple sub-carriers and multiple symbol periods in the resource segment. Using larger transmit power to reduce interference requests can improve detection performance. Time and frequency extension can provide diversity, which can also improve detection performance. The message transmission scheme 600 can also handle multiple conflicts of interference reduction requests. If multiple transmitter stations send interference reduction requests in the same resource segment, the receiver station can detect the interference reduction requests from each transmitter station and respond to each interference reduction request.

In the third design solution, frequency extension can be used to send a request to reduce interference. The interference reduction request can be processed (e.g., encoding and modulation) to obtain modulation symbols. Each modulation symbol can be expanded to obtain the corresponding data sequence. The data sequence of each modulation symbol can be transmitted through a set of sub-carriers to achieve frequency expansion.

FIG. 7 shows a design scheme of a message transmission scheme 700 using frequency extension. The transmission time axis can be divided into units of sub-frames. Each sub-frame may have a predetermined duration (for example, one millisecond (ms)), and each sub-frame may be divided into two time slots. The two time slots of a subframe include 14 symbol periods with indexes 0 to 13 for the common cyclic prefix in LTE. Multiple resource blocks can be specified for each time slot. Each resource block may include N sub-carriers (for example, 12 sub-carriers) in one time slot of LTE.

In a design scheme, the interference reduction request can be coded to obtain coded bits, and then these coded bits can be mapped to ten modulation symbols<i>d</i>(0) to<i>d</i>(9). These ten modulation symbols can be used to generate ten data sequences, as shown below:

<i>c</i>_<i>t</i>(<i>n</i>)<i>=d</i>(<i>t</i>)‧<i>r</i>(<i>n</i>),in<i>n</i>=0,...,N-1,<i>t</i>=0,...,9 equation (1)

in:<i>r</i>(<i>n</i>) Is a reference signal sequence of length N,<i>d</i>(<i>t</i>) Is the t-th modulation symbol used to reduce the interference request,<i>c</i>_<i>t</i>(<i>n</i>) Is the t-th data sequence used to reduce the interference request.

A set of reference signal sequences with zero or low cross-correlation characteristics can be specified. For example, the set may include Zadoff-Chu sequence, Chu sequence, Frank sequence, Generalized Chirp (GCL) sequence, Walsh sequence, M sequence, and so on. Different transmitter stations can use different reference signal sequences to simultaneously transmit interference reduction requests, and these reference signal sequences can be regarded as orthogonal sequences. The receiver station can detect the interference reduction request by coherently detecting the reference signal sequence used for each transmitted interference reduction request.

These ten modulation symbols can be used separately<i>d</i>(0) to<i>d</i>(9) to get ten data sequences<i>c</i>₀(<i>n</i>)arrive<i>c</i>₉(<i>n</i>). As shown in FIG. 7, these ten data sequences can be sent in two resource blocks, where the two resource blocks occupy different sets of subcarriers to achieve frequency diversity. As shown in Figure 7, for the first resource block in the left time slot, five data sequences can be sent in symbol periods 0, 2, 3, 4, and 6.<i>c</i>₀(<i>n</i>)arrive<i>c</i>₄(<i>n</i>), the reference signal sequence is sent in symbol periods 1 and 5<i>r</i>(<i>n</i>). As also shown in Figure 7, for the second resource block in the right time slot, five data sequences can be sent in symbol periods 7, 9, 10, 11, and 13.<i>c</i>₅(<i>n</i>)arrive<i>c</i>₉(<i>n</i>), the reference signal sequence is sent in symbol periods 8 and 12<i>r</i>(<i>n</i>)。

For the third design solution, the receiver station can detect the interference reduction request as shown below. For each resource block, a channel estimate can be derived from the reference signal sequence received in the resource block, and the channel estimate includes the channel gains of the N sub-carriers in the resource block. Subsequently, the channel estimation can be used to perform coherent demodulation on each received data sequence to obtain the corresponding detected data sequence. Coherent demodulation can remove the influence of channel gain from the received data sequence. Ten detected data sequences can be obtained from two resource blocks in a sub-frame. The ten detected data sequences can be correlated with each possible reference signal sequence to obtain a set of ten despread symbols for the reference signal sequence, and each detected data sequence corresponds to a despread symbol . Each despreading symbol set whose received power exceeds the power critical value can be saved, and the remaining despreading symbol sets can be discarded. For each saved set of despreading symbols, a logarithmic probability ratio (LLR) can be calculated based on the ten despreading symbols, and the despreading symbols can be decoded to obtain the interference reduction request sent in two resource blocks.

Figure 7 shows a specific design scheme that uses frequency extension to send a request to reduce interference. Generally speaking, the interference reduction request can be extended to obtain any number of data sequences, which can be sent in a sufficient number of resource units. The reference signal sequence can be sent in a sufficient number of symbol periods and on a sufficient number of sub-carriers, and the reference signal sequence can be used for coherent detection of the data sequence.

In another aspect, power control of the interfering station can be achieved by reducing the interference request. In a design scheme that interferes with the power control of the UE, the serving base station can use the transmit power level<i>P</i>_<i>TX</i>_{_}_<i>msg</i>To send a request to reduce interference, where<i>P</i>_<i>TX</i>_{<i>_</i>}_<i>msg</i>Determined as follows:

<maths><img file="TW201014287A_D0003.tif" /></maths>

in<i>P</i>_<i>C</i>Is the reference value described below,<i>I</i>_{<i>target</i>}It is the target interference level for the serving base station.

Interfering UE can receive power level<i>P</i>_<i>RX</i>_{<i>_</i>}_<i>msg</i>To receive the interference reduction request, where<i>P</i>_<i>RX</i>_{<i>_</i>}_<i>msg</i>Can be expressed as:

<maths><img file="TW201014287A_D0004.tif" /></maths>

in<i>h</i>It is the channel gain from serving base station to interfering UE.

The interfering UE can agree to reduce the interference request and determine its transmit power according to the following formula<i>P</i>_<i>d</i>：

<maths><img file="TW201014287A_D0005.tif" /></maths>

Interfering UE can use the value<i>P</i>_<i>d</i>Or lower transmit power for data transmission. Subsequently, assuming only one interfering UE and symmetrical downlink and uplink channels, the data transmission from the UE causes a value at the serving base station<i>I</i>_{<i>target</i>}Or lower interference.

The power control of the interfering base station can be performed in a similar manner. UE can transmit power level<i>P</i>_<i>TX</i>_{<i>_</i>}_<i>msg</i>To send a request to reduce interference. Interfering base station can receive power level<i>P</i>_<i>RX</i>_{<i>_</i>}_<i>msg</i>To receive a request to reduce interference. The interfering base station can agree to the request and reduce its transmit power to<i>P</i>_<i>d</i>Or lower. Subsequently, assuming an interfering base station and symmetrical downlink and uplink channels, the data transmission from the interfering base station causes a value for the UE<i>I</i>_{<i>target</i>}Or lower interference.

For power control, a transmit power with a request to reduce interference can be set, so that the target interference level can be achieved at the sending end of the request. The target interference level can be selected according to the expected data performance, and the target interference level can be set to solve the errors in multiple interfering stations, weaken the imbalance between the downlink and the uplink, and calibrate the interference at different stations. The error between the transmitting chain and the receiving chain, etc.

In a design scheme, all base stations can use the same<i>P</i>_<i>C</i>value. In another design scheme, base stations of different power levels can use different<i>P</i>_<i>C</i>value. For example, a high-power macro base station can use the first<i>P</i>_<i>C</i>Value, low-power pico base stations and femto base stations can use the second<i>P</i>_<i>C</i>Value, the second of which<i>P</i>_<i>C</i>Value is lower than first<i>P</i>_<i>C</i>value. In a design scheme, all UEs can use the same<i>P</i>_<i>C</i>Value, the<i>P</i>_<i>C</i>The value can be used with the base station<i>P</i>_<i>C</i>The value matches or does not match. In a design scheme, multiple sub-carrier sets can be reserved for sending interference reduction requests, and different<i>P</i>_<i>C</i>The value can be used for different reserved subcarrier sets. The UE may select a sub-carrier in the set of sub-carriers reserved for sending the interference reduction request according to the distance from the UE to the interfering base station.

FIG. 8 shows a design scheme of a process 800 for sending a signal in a wireless network. The process 800 may be performed by a transmitter station, which may be a base station, UE, repeater, or some other entity. The transmitter station may determine the set of subcarriers reserved for sending the signaling message (block 812). In one design solution, the signaling message may include an interference reduction request, which requires at least one interfering station to reduce interference to the transmitter station. The warning message can also include some other types of messages.

The transmitter station may select at least one sub-carrier in the set of sub-carriers based on the signaling message (block 814). In one design, the signaling message can have a value in the range of 0 to M-1, where M is greater than 1. Indexes 0 to M-1 can be assigned to the sub-carriers in the sub-carrier set. Subsequently, the transmitter station can select the subcarrier with index X according to the value X of the signaling message, where X is in the range of 0 to M-1.

The transmitter station may transmit a signal (e.g., a continuous phase signal) on at least one sub-carrier in multiple symbol periods to transmit a signaling message (block 816). In one design, the transmitter station may transmit the signal to at least one receiver station that performs asynchronous operation with the transmitter station. The transmitter station can set the transmission power of the signal to achieve good detection performance. As mentioned above, the transmission power can also be set according to the target interference level of the transmitter station.

In one design, multiple sub-carrier sets can be reserved for base stations with different power classes to send signaling messages. Subsequently, the transmitter station can select one of the multiple sub-carrier sets according to its power class. In another design solution, multiple subcarrier sets can be reserved for sending signaling messages at different transmit power levels. Subsequently, the transmitter station can select one of the multiple sub-carrier sets based on the transmit power used for the signaling message. In another design, multiple sub-carrier sets can be reserved for sending signaling messages in different cell service areas of the wireless network. Subsequently, the transmitter station can select one of the multiple sub-carrier sets according to the cell service area for the signaling message. Multiple sets of sub-carriers can also be reserved for other standards. In an alternative design scheme, a single set of subcarriers can be reserved for all base stations to send signalling messages, for all transmission power levels to send signalling messages, for all cell service areas to send signalling messages, and so on.

FIG. 9 shows a design scheme of a device 900 for sending a signal in a wireless network. The device 900 includes: a module 912 for determining a set of subcarriers reserved for sending a signaling message (for example, a request to reduce interference); a module 914 for selecting at least one subcarrier in the subcarrier set according to the signaling message; The module 916 is used to send a signal on at least one sub-carrier in multiple symbol periods to transmit a signaling message.

FIG. 10 shows a design scheme of a process 1000 of receiving a signal in a wireless network. Process 1000 may be performed by a receiver station, which may be a base station, UE, repeater, or some other entity. The receiver station may determine the set of subcarriers reserved for sending the signaling message (block 1012). The receiver station can obtain the received symbols of each subcarrier in the subcarrier set (block 1014). In one design, the receiver station can perform asynchronous operation with the transmitter station that sends the signaling message, and the receiver station can obtain the received symbol of each subcarrier according to its symbol timing. The receiver station can determine the received power of each sub-carrier based on the received symbol of the sub-carrier (block 1016)

The receiver station can detect the signaling message sent on the set of sub-carriers based on the received power of each sub-carrier (block 1018). Each signaling message can be sent on at least one specific subcarrier in multiple symbol periods. In one design, the receiver station can compare the received power of each subcarrier with a critical value. The receiver station can detect the signaling message on each subcarrier whose received power exceeds the critical value. The receiver station can obtain the information of each detected signaling message according to the specific subcarrier on which the signaling message is detected.

In a design scheme, the receiver station can determine multiple subcarrier sets reserved for the following reasons: sending signalling messages at different transmit power levels, sending signalling messages by base stations with different power classes, Send signal messages and so on in the cell service area. The receiver station can detect the signaling message sent on each sub-carrier in the plurality of sub-carrier sets.

In one design, the receiver station can obtain the interference reduction request from the detected signaling message (block 1020). The receiver station may reduce its transmit power in response to the interference reduction request (block 1022). In one design, the receiver station can determine the received power of the detected interference reduction request. Subsequently, as described above, the receiver station can determine its transmission power based on the detected received power of the interference reduction request.

FIG. 11 shows a design scheme of an apparatus 1100 for receiving a signal in a wireless network. The device 1100 includes: a module 1112 for determining a set of sub-carriers reserved for sending a signaling message; a module 1114 for obtaining the received symbol of each sub-carrier of the sub-carrier set; and a module 1116 for determining The received symbol of each sub-carrier in the sub-carrier set determines the received power of the sub-carrier; the module 1118 is used to detect the received power of each sub-carrier in the sub-carrier set according to the received power of each sub-carrier in the sub-carrier set. Signaling message; module 1120, used to obtain a request to reduce interference from the detected signal message; module 1122, used to reduce the transmission power according to the reduced interference request.

FIG. 12 shows a design scheme of a process 1200 of sending a signal in a wireless network. The process 1200 may be performed by a first station, which may be a base station, UE, repeater, or some other entity. The first station may generate an interference reduction request that requires at least one interfering station to reduce interference to the first station (block 1212). The first station may determine an orthogonal resource for the interference reduction request from among the plurality of orthogonal resources available for sending the interference reduction request (block 1214). The first station may send a request to reduce interference to at least one interfering station based on the orthogonal resources (block 1216).

In a design solution, the orthogonal resource may include an orthogonal sequence selected from a plurality of orthogonal sequences. In another design solution, the orthogonal resource may include a time interval selected from a plurality of time intervals. In another design solution, the orthogonal resource may include one frequency resource selected from a plurality of frequency resources. Generally speaking, orthogonal resources can include any code, time, frequency, and/or other resources.

In one design solution, orthogonal resources may include orthogonal sequences. The first station can extend the interference reduction request into one resource segment according to the orthogonal sequence. The resource segment can cover multiple sub-carriers in multiple symbol periods. The first station may generate a signal including a request to reduce interference extended into the resource segment. Subsequently, the first station can send the signal to at least one interfering station.

In a design solution, the first station may select an orthogonal sequence from a plurality of orthogonal sequences according to the message value of the interference reduction request. Subsequently, the first station may map the selected orthogonal sequence to the resource segment, for example, as shown in FIG. 6. In another design solution, the orthogonal resource may include a reference signal sequence. The first station can process the interference reduction request to obtain multiple modulation symbols. The first station can use the reference signal sequence to spread multiple modulation symbols to obtain multiple data sequences, and each modulation symbol corresponds to a data sequence, for example, as shown in equation (1). The first station can map multiple data sequences to resource segments, where each data sequence is mapped to multiple sub-carriers in one symbol period, for example, as shown in FIG. 7. The first station can also extend the interference reduction request to time and/or frequency in other ways. For example, the first station may extend the interference reduction request on one sub-carrier to the time domain of multiple symbol periods, in one symbol period to the frequency domain of multiple sub-carriers, and so on.

In a design solution, the first station may determine the transmit power used to reduce the interference request according to the target interference level of the first station. Subsequently, the first station can send a request to reduce interference according to the determined transmit power. In another design solution, the first station can send a request to reduce interference at a fixed transmit power level.

In a design scheme, the first station may send the interference reduction request as a unicast message to each interfering station. In another design, the first station may send the request to reduce interference as a broadcast message to all interfering stations. The first station may send a request to reduce interference on the physical uplink control channel (PUCCH) in LTE or some other channel.

FIG. 13 shows a design scheme of an apparatus 1300 for sending a signal in a wireless network. The device 1300 includes: a module 1312, configured to generate a request for reducing interference, which requires at least one interfering station to reduce interference to the first station; The orthogonal resource used for the interference reduction request is determined in the cross resource; the module 1316 is configured to send the interference reduction request to the at least one interfering station according to the orthogonal resource.

FIG. 14 shows a design scheme of a process 1400 of receiving a signal in a wireless network. The process 1400 may be performed by a first station, which may be a base station, a UE, a repeater, or some other entity. The first station may detect the request for reducing interference sent based on the orthogonal resources available for sending the request for reducing interference (block 1412). The available orthogonal resources may include code, time, frequency, and/or other resources. In a design solution, the available orthogonal resources may include multiple orthogonal sequences. The first station may obtain received symbols from resource segments covering multiple sub-carriers in multiple symbol periods. The first station can despread the received symbols according to multiple orthogonal sequences to obtain multiple despread symbols. Subsequently, the first station can detect the interference reduction request sent in the resource segment based on the multiple despreading symbols.

The transmitter station may send the request for reducing interference by using one of a plurality of orthogonal sequences to extend the request for reducing interference into the resource segment. The first station may despread the received symbols in a manner complementary to the spreading performed by the transmitter station. In a design scheme of block 1412, which is applicable to the design scheme shown in FIG. 6, the first station may use each orthogonal sequence to despread the received symbols to obtain corresponding despread symbols. The first station may determine the received power of each despreading symbol, and announce a request to reduce interference for each despreading symbol whose received power exceeds the critical value.

In another design scheme of block 1412, where this scheme is applicable to the design scheme shown in FIG. 7, the first station can use each orthogonal sequence to despread the received symbols in each symbol period of the resource segment, so as to Obtain the despread symbol of each orthogonal sequence in the two symbol period. The first station can determine the received power of each orthogonal sequence according to the despreading symbol of the orthogonal sequence. For each orthogonal sequence whose received power exceeds the critical value, the first station decodes all despread symbols obtained by using the orthogonal sequence to recover the detected interference reduction request.

The first station may reduce its transmit power based on the detected interference reduction request (block 1414). In a design solution, as described above, the first station may determine the received power of the detected interference reduction request, and then determine its transmission power based on the detected received power of the interference reduction request. The first station can also determine its transmit power in other ways.

FIG. 15 shows a design scheme of an apparatus 1500 for receiving a signal in a wireless network. The device 1500 includes: a module 1512 for detecting an interference reduction request sent according to orthogonal resources available for sending an interference reduction request; a module 1514 for reducing the transmission power of the first station according to the detected interference reduction request .

The modules in FIGS. 9, 11, 13 and 15 may include processors, electronic devices, hardware devices, electronic components, logic circuits, memory, software codes, firmware codes, etc., or any combination thereof.

FIG. 16 shows a block diagram of a design scheme of the base station 110 and the UE 120, where the base station 110 and the UE 120 are a base station and a UE in FIG. 1, respectively. The base station 110 is equipped with U antennas 1634a to 1634u, and the UE 120 is equipped with V antennas 1652a to 1652v, where usually<img file="TW201014287A_D0006.tif" />and<img file="TW201014287A_D0007.tif" />。

At the base station 110, the transmit processor 1620 receives data for one or more UEs from a data source 1612, and processes the data (for example, encoding, interleaving, and modulation) to provide data symbols. The transmitting processor 1620 may also receive control information (for example, the messages shown in FIG. 2 and FIG. 3) from the controller/processor 1640, process the control information, and provide control symbols. The transmit processor 1620 may also generate reference signal symbols for one or more reference signals or pilot frequencies. The transmit (TX) multiple input multiple output (MIMO) processor 1630 can perform spatial processing (for example, precoding) on these data symbols, control symbols and/or reference signal symbols (if any), and can modulate U number MOD 1632a to 1632u provide U output symbol streams. Each modulator 1632 can process a respective output symbol stream (for example, for OFDM, etc.) to obtain an output sample stream. Each modulator 1632 may further process (for example, convert into analog signals, amplify, filter, and up-convert) these output sample streams to obtain downlink signals. U downlink signals from modulators 1632a to 1632u may be transmitted via antennas 1634a to 1634u, respectively.

At UE 120, antennas 1652a to 1652v receive downlink signals from base station 110, and provide the received signals to demodulators (DEMODs) 1654a to 1654v, respectively. Each demodulator 1654 adjusts (e.g., filters, amplifies, down-converts, and digitizes) the respective received signal in order to obtain input samples. Each demodulator 1654 can further process these input samples (e.g., for OFDM, etc.) in order to obtain the received symbols. The MIMO detector 1656 can obtain received symbols from all V demodulators 1654a to 1654v, perform MIMO detection on these received symbols (if any), and provide the detected symbols. The receiving processor 1658 may process (for example, demodulate, deinterleave, and decode) the detected symbols, provide the decoded data of the UE 120 to the data slot 1660, and provide the decoded control information to the controller/processor 1680.

On the uplink, at the UE 120, the transmit processor 1664 can receive data from the data source 1662 and process it, and receive control information from the controller/processor 1680 and process it. The transmit processor 1664 may also generate reference signal symbols for one or more reference signals. These symbols from the transmitting processor 1664 can be pre-coded by the TX MIMO processor 1666 (if any), further processed by the modulators 1654a to 1654v, and transmitted to the base station 110. At the base station 110, these uplink signals from the UE 120 are received by the antenna 1634, processed by the demodulator 1632, detected by the MIMO detector (if any), and further processed by the receiving processor 1638 for Obtain the data and control information sent by the UE 120.

The controller/processors 1640 and 1680 can direct the operation of the base station 110 and the UE 120, respectively. The processor 1640 and/or other processors and modules of the base station 110 may execute or direct the process 800 in FIG. 8, the process 1000 in FIG. 10, the process 1200 in FIG. 12, the process 1400 in FIG. 14, and/or Other processes used in the techniques described in this application. The processor 1680 and/or other processors and modules of the UE 120 may also execute or direct the process 800, the process 1000, the process 1200, the process 1400, and/or other processes used in the technology described in this application. The memories 1642 and 1682 can store data and program codes for the base station 110 and the UE 120, respectively. The scheduler 1644 may schedule the UE for data transmission on the downlink and uplink, and provide resource authorization for the scheduled UE.

Those skilled in the art should understand that information and signals can be represented using any of a variety of different technologies and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof .

Those skilled in the art should also understand that the various exemplary logic blocks, modules, circuits, and algorithm steps described in conjunction with the disclosure of this application can all be implemented as electronic hardware, computer software, or a combination of both. In order to clearly show the interchangeability between hardware and software, various exemplary components, blocks, modules, circuits, and steps are described above in general around their functions. As for whether this function is implemented as hardware or software, it depends on the specific application and the design constraints imposed on the entire system. Skilled artisans can implement the described functions in a flexible manner for each specific application, but this implementation decision should not be interpreted as a departure from the protection scope of the present invention.

General-purpose processors, digital signal processors (DSP), special integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, individual gates or transistor logic used to perform the functions described in this application Devices, individual hardware components, or any combination thereof can implement or execute various exemplary logic block diagrams, modules, and circuits described in conjunction with the disclosure of this application. The general-purpose processor may be a microprocessor, or the processor may also be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, a combination of one or more microprocessors and a DSP core, or any other such structure.

The steps of the method or algorithm described in combination with the content disclosed in this application can be directly embodied as hardware, a software module executed by a processor, or a combination of the two. The software module can be located in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, scratchpad, hard disk, removable disk, CD-ROM or any other known in the art Form of storage media. An example storage medium can be coupled to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Alternatively, the storage medium may also be an integral part of the processor. The processor and storage medium can be located in the ASIC. The ASIC can be located in the user terminal. Of course, the processor and the storage medium may also exist as individual components in the user terminal.

In one or more exemplary design solutions, the functions described in this application can be implemented by hardware, software, firmware, or any combination thereof. When implemented by software, these functions can be stored as one or more instructions or codes in a computer readable medium or transmitted as one or more instructions or codes on a computer readable medium. Computer readable media include computer storage media and communication media, where these media include any media that facilitates the transfer of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, floppy disk storage media or other magnetic disk storage devices, or can be used to command Or any other medium that carries or stores the desired program code module in the form of a data structure, and these mediums can be accessed by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. In addition, any connection can be appropriately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, wireless, and microwave, then the coaxial cable , Fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, wireless, and microwave are also included in the definition of the media. As used in this application, disks and discs include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVD), floppy discs, and Blu-ray discs, in which disks are usually copied magnetically Data, and optical discs use lasers to optically copy data. The above combination should also be included in the protection scope of computer readable media.

In order to enable those of ordinary skill in the art to implement or use the present invention, the above description is based on the disclosure of the present invention. For those skilled in the art, various modifications to these contents are obvious, and the general principles defined in this application can also be applied to other modifications without departing from the spirit or protection scope of the present invention. Therefore, the present invention is not limited to the examples and design solutions described in this application, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

<p>812. . . Determine the set of subcarriers reserved for sending signaling messages (for example, requests to reduce interference)</p><p>814. . . Select at least one sub-carrier in the set of sub-carriers based on the signaling message</p><p>816. . . Send a signal on at least one sub-carrier in multiple symbol periods to transmit a signaling message</p><p>912. . . A module used to determine the set of subcarriers reserved for sending signaling messages (for example, requests to reduce interference)</p><p>914. . . A module for selecting at least one sub-carrier in the set of sub-carriers based on the signaling message</p><p>916. . . Module for sending signals on at least one sub-carrier in multiple symbol periods to transmit signaling messages</p><p>1012. . . Determine the set of subcarriers reserved for sending signaling messages</p><p>1014. . . Obtain the received symbol of each sub-carrier in the sub-carrier set</p><p>1016. . . Determine the received power of the sub-carrier according to the received symbol of each sub-carrier in the sub-carrier set</p><p>1018. . . According to the received power of each sub-carrier to detect the signaling message sent on the sub-carrier set</p><p>1020. . . Obtain the interference reduction request from the detected signal</p><p>1022. . . Reduce the transmit power according to the interference reduction request</p><p>1112. . . Module used to determine the set of subcarriers reserved for sending signaling messages</p><p>1114. . . Module for obtaining the received symbol of each sub-carrier in the sub-carrier set</p><p>1116. . . A module for determining the received power of the sub-carrier according to the received symbol of each sub-carrier in the sub-carrier set</p><p>1118. . . A module used to detect the signaling message sent on the sub-carrier set according to the received power of each sub-carrier</p><p>1120. . . Module used to obtain interference reduction request from detected signal messages</p><p>1122. . . A module used to reduce the transmission power according to the interference reduction request</p><p>1212. . . Generate a request for reducing interference, which requires at least one interfering station to reduce interference to the first station</p><p>1214. . . Determine the orthogonal resource used for the interference reduction request from a plurality of orthogonal resources available for sending the interference reduction request</p><p>1216. . . Sending a request for reducing interference to at least one interfering station based on the orthogonal resource</p><p>1312. . . A module for generating a request for reducing interference, where the request for reducing interference requires at least one interfering station to reduce interference to the first station</p><p>1314. . . A module for determining the orthogonal resource used for the interference reduction request from a plurality of orthogonal resources available for sending the interference reduction request</p><p>1316. . . Module for sending interference reduction request to at least one interference station based on the orthogonal resource</p><p>1412. . . Detection of interference reduction requests sent based on orthogonal resources that can be used to send interference reduction requests</p><p>1414. . . Reduce the transmission power of the first station according to the detected interference reduction request</p><p>1512. . . A module for detecting interference reduction requests sent based on orthogonal resources that can be used to send interference reduction requests</p><p>1514. . . A module used to reduce the transmit power of the first station based on the detected interference reduction request</p><p>1612. . . Data source</p><p>1620. . . Launch processor</p><p>1630. . . TX MIMO processor</p><p>1636. . . MIMO detector</p><p>1638. . . Receiving processor</p><p>1639. . . Data slot</p><p>1640. . . Controller/Processor</p><p>1642. . . Memory</p><p>1644. . . Scheduler</p><p>1632a. . . Modulator/demodulator</p><p>1632u. . . Modulator/demodulator</p><p>1654a. . . Demodulator/modulator</p><p>1654v. . . Demodulator/modulator</p><p>1656. . . MIMO detector</p><p>1658. . . Receiving processor</p><p>1660. . . Data slot</p><p>1662. . . Data source</p><p>1664. . . Launch processor</p><p>1666. . . TX MIMO processor</p><p>1680. . . Controller/Processor</p><p>1682. . . Memory</p>

Figure 1 shows a wireless communication network.

Figure 2 shows downlink data transmission with interference mitigation.

Figure 3 shows uplink data transmission with interference mitigation.

Figures 4A and 4B show frequency resources reserved for signaling messages.

Figure 5 shows message transmission using sub-carrier mapping.

Figure 6 shows message transmission using time and frequency extension.

Figure 7 shows a message transmission scheme using frequency extension.

Figure 8 shows the process of using sub-carrier mapping to send a signal.

Figure 9 shows a device that uses sub-carrier mapping to send a signal.

Figure 10 shows the process of receiving a signal using sub-carrier mapping.

Figure 11 shows a device that uses sub-carrier mapping to receive a signal.

Figure 12 shows the process of using extensions to send a signal.

Figure 13 shows a device that uses extensions to send a signal.

Figure 14 shows a process for receiving a signal sent using the extension.

Figure 15 shows a device for receiving a signal sent using an extension.

Figure 16 shows a block diagram of a base station and a UE.