Uplink feedback channel reporting mechanism in wireless sytems

Wireless portable broadband communication systems may use uplink feedback channels to assist in closed-loop operations. For example, systems that comply with the Institute of Electrical and Electronic Engineers (IEEE) 802.16m standard specify two types of feedback channels to assist in closed-loop multiple input and multiple output (MIMO) operations. One type of channel is referred to as the primary high speed feedback channel and the other type of channel is referred to as the secondary high speed feedback channel. The primary fast feedback channel utilizes sequence modulation to carry 4-6 bits in a 6x6 uplink controlled distributed resource unit (DRU). The secondary fast feedback channel is coherent to transmit 7 to 24 bits in a 6x6 DRU. detection) is used. The primary fast feedback channel is more robust than the secondary fast feedback channel, but the secondary fast feedback channel has higher throughput than the primary fast feedback channel. The Feedback Advanced Map (A-MAP) Assignment Information Element (IE) is used to assign and deallocate feedback channels to a particular mobile station (MS). If periodic allocation is implemented, the base station (BS) defines the transmission cycle and transmission period. Due to the limited signal bit length, the transmission period is usually 4^pIt is an exponential expression such as a period. For example, when p is 3 bits, the transmission period ranges from 1 cycle to 16384 frames.

Deassignment may be associated with the base station determining whether the mobile station needs to send feedback according to the previous assignment. As an example of a scenario, consider the case where a user cancels the download of a large file. If the allocation is very long and there is a 1% chance that the mobile station will fail to deallocate the A-MAP IE, the mobile station will transmit on the unassigned feedback channel without the base station knowing. May continue. In such cases, unnecessary interference may occur and collisions may occur in the deallocated feedback channels. From the base station's point of view, the lost deallocation A-MAP IE may be detected by the detection of a collision on the deallocation feedback channel. However, detection is possible in the case of a high-performance base station implementation, and it is necessary to guarantee the reliability of detection for a plurality of cycles. In the worst-case scenario, the base station does not detect a collision and the mobile station continues to transmit on the deallocated feedback channel until the allocation cycle expires.

In the specification, the features described in the claims are specifically described, and the claims are clearly claimed in the claims attached to the specification. These features will be understood by reference to the detailed description below and the accompanying drawings.

<figref num="1">It is a block diagram of the channel feedback system which can implement the feedback channel release to the wireless network which concerns on one or more embodiments.</figref><figref num="2">It is a block diagram of the wireless wide area network which uses the channel feedback system which concerns on one or more embodiments.</figref><figref num="3">It is a block diagram of the release confirmation process of feedback allocation release which concerns on one or more embodiments.</figref><figref num="4">It is a flowchart of the method of implementing the feedback channel release which concerns on one or more embodiments.</figref><figref num="5">It is a block diagram of the information handling system which can implement the feedback channel release which concerns on one or more embodiments.</figref>

For the sake of simplification and / or clarity of illustration, the elements illustrated are not necessarily drawn in actual dimensions. For example, the dimensions of some elements may be magnified compared to other elements for clarity. In addition, reference numbers are repeatedly used between drawings to indicate corresponding and / or similar elements where deemed appropriate.

In the following detailed description, many details are provided to provide a complete understanding of the claimed features. However, it will be apparent to those skilled in the art that the present invention can be carried out without these details. Further, for the purpose of not obscuring the present invention, detailed description of well-known methods, procedures, components, circuits and the like is omitted.

In the following description and / or claims, the terms "coupled" and "connected", as well as their derivatives, may be used. In certain embodiments, "connection" is used to refer to two or more elements being in direct physical or electrical contact with each other. "Connecting" also refers to the direct physical or electrical contact of two or more elements. However, "linkage" also means that two or more elements are not in direct contact with each other, but are cooperating or interacting with each other. For example, "concatenated" means that two or more elements do not touch each other, but are indirectly connected via another or intermediate element. In addition, the terms "on", "overlying", and "over" may be used in the following description and claims. "On", "overlying", "over" means that two or more elements are in direct physical contact with each other. However, "over" also means that two or more elements do not come into direct contact with each other. For example, "over" means that one element is above another, does not touch each other, and there is another one or more elements between these two elements. Means. Also, the words "and / or" are "and", "or", "exclusive or", "one", "some not all", "neither" , And / or "both are", but the claims are not limited in this regard. In addition, in the following description and / or claims, "comprise", "include" and their derivatives are used as synonyms with each other.

FIG. 1 is a block diagram of a channel feedback system that can implement feedback channel release to a wireless network according to one or more embodiments. As shown in FIG. 1, the channel feedback system 100 may include a base station 110 having one or more antennas 112 communicating with a mobile station 114 having one or more antennas 116. In one or more embodiments, base station 110 may transmit data packets to mobile station 114 via downlink (DL) channel 118. In the feedback configuration, the feedback may be provided from the mobile station 114 to the base station 110, and the feedback sequence is a two-tier adaptation including the primary uplink (UL) fast feedback channel 120 and the secondary uplink fast feedback channel 122. Includes feedback framework. The primary UL feedback channel 120 may provide wideband channel quality information (CQI) reports from mobile station 114 to transmitter for downlink channel 118 at sufficient data transfer rates. The secondary UL feedback channel 122 may use the adaptive transmit rate to provide subband CQI reports from mobile station 114 to base station 110. The secondary UL feedback channel 122 may utilize link adaptation with event-driven transmission to reduce overhead and increase transmission efficiency. The 2-channel feedback system 100, as shown in Figure 1, provides flexibility in independent high-speed feedback channel design to optimize the performance of each channel. For example, a two-channel feedback system can achieve optimal or near-optimal performance in different permutation modes, but the claims are not limited in this regard.

In one or more embodiments, the primary UL feedback channel 120 may be referred to as the primary CQI channel (PCQICH) and the secondary feedback channel 122 may be referred to as the secondary CQI channel (SCQICH). Relative to fit feedback information to different tile sizes to both simple has a design uncomplicated primary (PCQICH) fast feedback channels 120 and / or secondary (SCQICH) fast feedback channel 122, Bose and optimized Ray-Chaudhuri (BCH) codes may be used. In one or more embodiments, the primary fast feedback channel 120 may utilize, for example, a quasi-orthogonal sequence of length 12 to support information up to 6 bits with optimized performance. Larger diversity orders may be used. The mobile station 114 may support fast feedback channel transmission using, for example, non-coherent (synchronous) detection at high speeds exceeding 120 km / h (120 km / h), a patented feature. The scope is not limited in this regard.

In one or more embodiments, the primary CQI channel 120 may support slow, infrequent, periodic CQI feedback transmission from mobile station 114 to base station 110. The primary CQI channel 120 may transmit average CQI and / or multiple inputs and multiple outputs (MIMO) feedback information to provide a reliable basic connection from mobile station 114 to base station 110. The primary CQI channel 120 is available to all users who need CQI feedback on the uplink. For example, base station 110 allocates resources to the primary high-speed feedback channel 120 and provides feedback based on channel variation characteristics for each individual user, referred to as subscriber station or mobile station 114, which is materialized as mobile station 114. The frequency may be specified. Resource allocation information may be transmitted to mobile station 114 to control CQI feedback operation.

In one or more embodiments, the secondary fast feedback channel 122 may support more advanced features than the primary fast feedback channel 120, eg, is highly efficient, with multiple inputs and multiple outputs (MIMO), fractional frequency reuse. It supports partial frequency reuse), frequency selection scheduling (FSS), etc., and is used when there is data to be transmitted. In addition, the secondary fast feedback channel 122 may provide more frequent and finer CQI feedback than the primary fast feedback channel 120. That is, the secondary high-speed feedback channel 122 may support feedback of a high payload of CQI and MIMO feedback information in a narrow band, and this information includes MIMO effective signal-to-noise ratio (SINR) per code word, transmission. Rank, precoding matrix index (PMI), etc. may be included as needed and the transmission may be event driven. To maximize the throughput of the secondary high-speed feedback channel 122 while ensuring robust transmission, the secondary high-speed feedback channel 122 utilizes link application, and the link application is applied to the user and channel state to improve the feedback efficiency. It is based on at least part of it. In such a configuration, the central user may utilize the relatively high SINR to efficiently transmit the CQI at a high data rate. The secondary fast feedback channel 122 may then cover users with localized resource allocation via the downlink channel 118, which may include more CQIs to support features such as FSS, MIMO, etc. Accompanied by feedback. On the other hand, users with poor channel quality may not be able to achieve significant gain by using the secondary fast feedback channel 122 to feed back a large amount of CQI. For each request from the subscriber station, the base station 110 determines whether or not to allocate the secondary high-speed feedback channel 122, when to allocate the secondary high-speed feedback channel 122, the amount of resources involved, and the corresponding index and transmission frequency. , Transfer rate, etc. may be determined, such information The information may be transmitted to the mobile station 114. Further details of the channel feedback system 100 are described below. An example of a network that implements the channel feedback system 100 will be described below with reference to FIG.

FIG. 2 is a block diagram of a wireless wide area network using a channel feedback system that implements feedback channel release according to one or more embodiments. As shown in FIG. 2, the network 200 may be an Internet Protocol (IP) type network such as the Internet 210 type network capable of supporting mobile wireless access and / or fixed line access to the Internet 210. In one or more embodiments, the network 200 may comply with the Worldwide Interoperability for Microwave Access (WiMAX) standard or future generations of WiMAX, and in one particular embodiment, the Electrical and Electronic Engineers Association 802.11m standard (IEEE802). .16m) may be compliant. In one or more other embodiments, the network 200 is a 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) or 3GPP2 Air Interface Evolution (3GPP2). It may comply with the AIE) standard. Generally, the network 200 includes an orthogonal frequency division multiple access (OFDMA) based wireless network, but the scope of claims is not limited in this regard. As an example of mobile wireless access, the access service network (ASN) 212 can be combined with the base station (BS) 214 to provide wireless communication between the subscriber station (SS) 216 and the Internet 210. Subscriber station 216 may include a portable device or information handling system capable of wireless communication over network 200, including, for example, notebook computers, mobile phones, personal digital assistance, and the like. The ASN212 may implement a profile that can specify the mapping of network functionality to one or more physical entities on the network 200. Base station 214 may include radio equipment to provide radio frequency (RF) communication with subscriber station 216, for example, physical layer (PHY) and medium access control (MAC) conforming to the IEEE 802.11m standard. ) Including layer equipment. Base station 214 may further include an IP backplane for connecting to the Internet 210 via ASN 212, and the claims are not limited in this regard.

Network 200 is a visited connectivity service capable of providing one or more network functions, including but not limited to proxy and / or relay type functions. Network (CSN) 224 may be further included, and proxy and / or relay-type functions include, for example, authentication, authentication and recording (AAA) function, dynamic host configuration protocol (DHCP) function, domain name service control, and the like. Includes domain gateways such as Switched Telephone Network (PSTN) gateways or Voice over Internet Protocol (VOIP) gateways, and / or Internet Protocol (IP) -type server functions. The types of functions that can be provided by the visited CSN or the home CSN226 described above are merely examples, and the scope of claims is not limited in this regard. The visited CSN224 may be, for example, if the visited CSN224 is not part of the regular service provider of the subscriber station 216, if the subscriber station 216 roams away from a home CSN such as the home CSN226, or if the network 200 Although part of the subscriber station's normal service provider, network 200 may also be referred to as the visited CSN if it resides in another location or is not in the subscriber station 216's main or home location. Good. In a fixed radio arrangement, a home or home to the Internet 210 via base station 220, ASN 218 and home CSN 226 in a manner similar to access by subscriber station 216 via base station 214, ASN 212 and visited CSN 224. WiMAX customer premises equipment (CPE) 222 may be installed at home or at work to provide customer broadband access from the workplace. The difference is WiMAX The CPE222 can be moved and installed in different locations as needed, but is usually installed in a fixed location, whereas the subscriber station 216 is, for example, in the reception range from base station 214. As long as it exists, it can be used in more than one place. In one or more embodiments, the Operations Support System (OSS) 228 may be part of the network 200 to provide management functions for the network 200 and provide interfaces between the functional entities of the network 200. The network 200 of FIG. 2 is only one type of wireless network showing a certain number of components of the network 200, and the claims are not limited in this regard.

FIG. 3 is a block diagram of the feedback assignment release confirmation process according to one or more embodiments. FIG. 3 shows an example of the arrangement of the general configuration of the feedback allocation release confirmation according to one or more embodiments. In one or more embodiments, base station 110 transfers feedback to mobile station 114, eg, via downlink channel 118 as shown in FIG. 1, advanced map (A-MAP) information element (IE) 310. To send. The deallocation A-MAP IE transmitted from the base station 110 to the mobile station 114 is to the mobile station 114, for example, the primary uplink feedback channel 120 and / or the secondary uplink feedback channel 122 as shown in FIG. , Instruct to unassign the use of the feedback channel. Upon receiving the deallocation A-MAP IE310 from the base station 110, the mobile station 114 sends a feedback deallocation A-MAP to the base station 110 by sending a deallocation confirmation 312. After confirming that the IE310 has been received, the base station 110 can know whether the feedback channel has been properly deallocated. Thus, in one or more embodiments, after transmitting the feedback deallocation A-MAP IE 310 to the mobile station 114, the base station 110 is expected to receive the deallocation confirmation 312 from the mobile station. Upon receiving the deallocation confirmation 312, the base station may assign the feedback channel to another mobile station. However, if the base station 110 does not receive the deallocation confirmation 312, the base station assigns one or more feedbacks, if necessary, until the deallocation confirmation 312 is received or times out. Release A-MAP IE310 may be resent.

In one or more embodiments, the deallocation confirmation 312 transmitted from mobile station 114 to base station 110 may be defined using one codeword in the primary high speed feedback channel 120. Other special formats may be used for the deallocation confirmation 312, and the claims are not limited in this regard. Since the primary fast feedback channel 120 is more robust than the secondary fast feedback channel 122 in one or more embodiments, the deallocation confirmation 312 may be transmitted as one codeword in the primary fast feedback channel 120. Also, in one or more embodiments, the detection of the deallocation confirmation 312 is to determine whether a special deallocation confirmation 312 codeword has been transmitted or any other signal has been transmitted. , It can be said that it is more robust than normal primary high-speed feedback transmission.

An example of a system for deallocating feedback channels is shown in Table 1 below.<tables num="1-1"><img file="JP5382829B2_D0001.tif" /></tables><tables num="1-2"><img file="JP5382829B2_D0002.tif" /></tables><tables num="1-3"><img file="JP5382829B2_D0003.tif" /></tables>

As shown in Table 1, the feedback allocation A-MAP IE configuration includes an acknowledgment (ACK) allocation flag, for example, such that a hybrid automatic repeat request (HARQ) is provided on other systems. If the ACK allocation flag is equal to 1, the 6-bit HARQ feedback allocation (HFA) indicates the HARQ index. The mobile station 114 uses the indicated HARQ feedback channel to transmit the successful reception of the feedback deallocation A-MAP IE 312 to the base station 110. A method of implementing feedback channel release is described with reference to FIG.

FIG. 4 is a flowchart of a method of implementing feedback channel release according to one or more embodiments. The order of method 400 shown in FIG. 4 is an example, and other orders may be implemented in the same manner, and may include blocks other than those shown in FIG. 4 or fewer blocks shown in FIG. The scope of the features is not limited in this regard. As shown in FIG. 4, in the block 410, a communication link is established between the base station 110 and the mobile station 114. At block 412, base station 110 transmits feedback allocation A-MAP IE 310 to mobile station 114 to allocate feedback channels to be utilized by mobile station 114 for various communications. Various communications include, for example, transmission of channel quality information (CQI), various hybrid automatic repeat request (HARQ) messages, and / or other feedback transmissions that support multiple input multiple output (MIMO) communications. .. In one or more embodiments, in block 414, mobile station 114 sends feedback allocation A-MAP to mobile station 114. According to IE310, the Fordback is transmitted to the base station 110 on the primary high-speed feedback channel 120 and / or the secondary high-speed feedback channel 122. In one or more embodiments, the feedback allocation includes an allocation period in which the feedback channel to which the mobile station 114 is assigned may be utilized, such as a short-term feedback period (p) or a long-term feedback period (q). At block 416, for example, a determination may be made as to whether feedback allocation should be terminated prior to the allocated feedback period. If it is not determined to end the allocation, the mobile station 114 continues to transmit feedback to the base station 110 based on the feedback allocation. If it is determined that the allocation is terminated, the feedback allocation is terminated, and in block 418, the base station 110 transmits the feedback allocation release A-MAP IE 310 to the mobile station 114. Feedback deallocation A-MAP Upon receiving the IE 310, in block 420, the mobile station 114 sends a deallocation confirmation 312 to the base station 110. At block 422, it may be determined whether the deallocation confirmation 312 has been received by the base station 110. If base station 110 does not receive allocation confirmation 312 from mobile station 114, at block 418, base station 110 resends feedback deallocation A-MAP IE 310 once more or several more times, as needed. And / or the mobile station 114 may resend the allocation confirmation 312 to the base station 110 once more or several more times, as needed. At block 424, the base station 110 transfers the feedback channel resource to another mobile station after the base station 110 receives the deallocation confirmation 422 or at the end of a predetermined timeout period or after a predetermined number of retransmissions. You may reassign. Method 400 may then be applied to feedback channel allocation and / or deallocation to another mobile station.

FIG. 5 is a block diagram of an information handling system in which feedback channel release can be implemented according to one or more embodiments. The information handling system 500 of FIG. 5 embodies one or more elements of the channel feedback system 100 described with reference to FIG. 1 and / or any network element of the network 200 shown in FIG. You may. For example, the information processing system 500 may represent the hardware of the base station 110 and / or the mobile station 114, with a large number or a small number of components depending on the hardware specifications of a particular device or network element. used. Although the information processing system 500 represents an example of a plurality of types of computing platforms, the information processing system 500 may include more or fewer components than those shown in FIG. And / or the components may be arranged in different ways, and the scope of the patentable features is not limited in this regard.

The information processing system 500 may include one or more processors such as processor 510 and / or processor 512 having one or more processing cores. One or more processors 510 and / or processor 512 via a memory bridge 514 provided outside the processor 510 and / or 512 or at least partially inside one or more of the processors 510 and / or 512. It may be combined with the above memory 516 and / or 518. Memory 516 and / or memory 518 may include various types of semiconductor-based memory, such as volatile and non-volatile memory. The memory bridge 514 may be coupled with the graphics system 520 to drive a display device (not shown) coupled with the information processing system 500.

The information processing system 500 may further include an input / output (I / O) bridge 522 that couples with various types of I / O systems. The I / O system 524 may further include, for example, a universal serial bus (USB) type system that connects the information processing system 500 and one or more peripheral devices, an IEEE1394 type system, and the like. The bus system 526 is a Peripheral component interconnect that couples the information processing system 500 with one or more peripheral devices. It may include one or more bus systems, such as (PCI) express buses. The hard disk drive (HDD) control system 528 may combine one or more hard disk drives or the like with an information processing system, such as a serial ATA type drive or the like, or flash memory, phase change memory and / or chalcogenide. A semiconductor-based drive including a type of memory or the like may be coupled. The switch 530 may be used to combine an I / O bridge 522, such as a Gigabit Ethernet device, with one or more switching devices. Further, as shown in FIG. 5, the information processing system 500 provides RF circuits and devices for wireless communication over a wireless network such as the channel feedback system 100 of FIG. 1 and / or with other wireless communication devices. The radio frequency (RF) 532 may be included and the information processing system 500 integrates the base station 110 and / or the mobile station 114, but the scope of the patentable features is not limited in this regard. Also, at least a portion of base station 110 or mobile station 114 may be implemented by processor 510, eg, digital functions of base station 110 or mobile station 114 that may include processing of baseband and / or orthogonal signals. Although implemented by the processor, the scope of patented features is not limited in this regard.

Although the claimed features have been described in detail, it will be apparent to those skilled in the art that the described components can be modified without departing from the claims and / or spirit. Feedback channel release and / or its associated use is understood by the above description and without departing from the spirit and scope of the claimed features or at the expense of the advantages of the components, form, structure and /. Or it is clear that various changes can be made in the arrangement of the components. The embodiments described above are merely embodiments for illustration that do not provide substantial further changes.