CN108353059A

CN108353059A - A kind of information feedback method and website

Info

Publication number: CN108353059A
Application number: CN201680063795.8A
Authority: CN
Inventors: 牛勇; 冯子奇; 冯薇; 李德建; 陈佳民
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-05-13
Filing date: 2016-05-13
Publication date: 2018-07-31
Also published as: WO2017193366A1

Abstract

A kind of information feedback method and website, this method are applied to the first website, and this method includes：The channel state information of N number of beam combination is measured, N is the integer more than 1；The information acquisition request of the second website transmission is received, which includes the first thresholding；According to the channel state information of each beam combination, the maximum beam combination of channel capacity in N number of beam combination is determined as object beam combination；According to the channel capacity and the first thresholding of object beam combination, the highest K beam combination of channel capacity is chosen from N number of beam combination, K is the integer more than or equal to 1, and less than N；The first information of K beam combination is sent to the second website.The embodiment of the present invention can reduce the capacity that the first website is sent to the information of the second website.

Description

Information feedback method and site

Technical Field

The present invention relates to the field of communications technologies, and in particular, to an information feedback method and a station.

Background

In the millimeter wave wireless communication technology field, a Station (STA) needs to configure an antenna with analog beamforming capability, for example: a phased array antenna or a group of antennas that can switch beam directions to improve antenna gain and extend communication distance. When two receiving STAs are respectively configured with Multiple Antenna arrays (Antenna arrays) or configured with a single Antenna Array including Multiple radio frequency chains, and there are Multiple analog beam combinations between the two receiving STAs, the analog beam combination for Multiple-Input Multiple-Output (MIMO) communication between the two STAs needs to be selected through analog beamforming training before the two STAs perform communication, so as to establish an effective channel. If two STAs are respectively configured with a plurality of Antenna arrays having a large number of Antenna elements (Antenna elements), each Antenna array may generate a plurality of analog beams, so that a plurality of beam pairs consisting of a transmission beam and a reception beam and a plurality of beam combinations consisting of a plurality of beam pairs exist between the two STAs. At present, after the analog beamforming training in the hybrid beamforming training, in order for the STA for transmitting the data frame to obtain the analog domain beamforming combination or the digital domain beamforming precoding through the channel measurement result of the analog beamforming training, the STA for receiving the data frame needs to send information of each beam pair in all the beam combinations determined through the analog beamforming training to the STA for transmitting the data frame, or send channel state information of all the beam combinations to the STA for transmitting the data frame, so that the data amount of the information sent by the STA for receiving the data frame to the STA for transmitting the data frame is large.

Disclosure of Invention

The embodiment of the invention discloses an information feedback method and a station, which are used for reducing the data volume overhead of information sent by an STA (station) used for receiving a data frame to the STA used for sending the data frame.

A first aspect discloses an information feedback method, which is applied to a first STA, measures channel state information of N beam combinations, receives an information acquisition request including a first threshold sent by a second STA, determines a beam combination with the largest channel capacity among the N beam combinations as a target beam combination according to the channel state information of each beam combination, selects K beam combinations with the highest channel capacity from the N beam combinations according to the channel capacity of the target beam combination and the first threshold, and sends first information of the K beam combinations to the second STA. Each beam combination corresponds to a MIMO effective channel, N beam combinations are all or partial beam combinations between the first STA and the second STA, N is an integer greater than 1, and K is an integer greater than or equal to 1 and less than N. The first STA is a receiver of the data frame, and the second STA is a sender of the data frame.

In one embodiment, when measuring the channel state information of N beam combinations, the channel coefficients of a plurality of beam pairs consisting of one transmit sector (sector) and one receive sector (rx sector) may be measured first, and then the channel matrix of each beam combination may be constructed according to the channel coefficients. The channel state information may be an effective channel matrix measured in the analog beamforming training process, one sector is a beam, and a beam combination may also be referred to as a sector combination. For the first STA or the second STA, the sector combinations may be represented by receive sector combinations or transmit sector combinations, respectively, and each sector combination/beam combination corresponds to one MIMO link. The transmission sector refers to a sector on the second STA, and the reception sector refers to a sector on the first STA.

In one embodiment, when determining a beam combination with the largest channel capacity among N beam combinations as a target beam combination according to the channel state information of each beam combination, the signal intensity gain of each beam combination may be calculated according to a channel matrix, M beam combinations may be selected from the N beam combinations, and the channel capacity of each beam combination of the M beam combinations may be calculated; and determining the beam combination with the largest channel capacity in the M beam combinations as the target beam combination. The signal strength gain is obtained according to a sum of the moduli or a sum of squares of the moduli of all elements (i.e., channel coefficients) in the channel matrix, the M beam combinations are beam combinations corresponding to the largest M signal strength gains among the N signal strength gains, and M is an integer greater than or equal to 1 and less than N. Since only the channel capacity of a part of the beam combinations (i.e., M beam combinations) needs to be calculated, generally M is much smaller than N, the number of times of calculating the channel capacity can be greatly reduced.

In one embodiment, when M beam combinations are selected from the N beam combinations, a determinant of a channel matrix of each of the N beam combinations may be calculated, L beam combinations having a determinant not less than a first preset value are selected from the N beam combinations, and M beam combinations are selected from the L beam combinations, where L is an integer greater than or equal to 1 and less than N, and M is less than or equal to L. Therefore, the beam combination with smaller channel capacity can be removed by calculating the determinant of the effective channel matrix to narrow the selection range of the beam combination, and the calculation amount required for calculating the channel capacity can be further reduced.

In one embodiment, when the first STA and the second STA only include one antenna array, the antenna array is connected to at least one radio frequency chain, and each radio frequency chain is connected to all antenna elements of the one antenna array, according to the channel state information of each beam combination, when a beam combination with the largest channel capacity among N beam combinations is determined as a target beam combination, the signal-to-noise ratio of each beam pair is determined, P beam pairs are selected from all beam pairs, the first channel capacity of the beam combination formed by the P beam pairs is calculated, a second beam pair with the largest signal-to-noise ratio is selected from the P beam pairs, the signal-to-noise ratio of a third beam pair is set to 0 to obtain all set beam pairs, I beam pairs are selected from all set beam pairs, I is equal to P, and transmission beams in the I beam pairs respectively belong to different radio frequency chains in the second STA, receiving beams in the I beam pairs respectively belong to different radio frequency chains in the first STA, each beam pair in the I beam pairs is the beam pair with the largest signal-to-noise ratio in the first beam pair, second channel capacity of a beam combination formed by the I beam pairs is calculated, and the beam combination corresponding to the larger value of the first channel capacity and the second channel capacity is determined as a target beam combination. The number of the first STA radio frequency chains is greater than that of the second STA radio frequency chains, the number of the second STA radio frequency chains is greater than that of the first STA radio frequency chains, the number of the first STA radio frequency chains is greater than that of the second STA radio frequency chains, and the number of the second STA radio frequency chains is greater than that of the second STA radio frequency chains. Since only the channel capacity of the combination of the two beams needs to be calculated, the number of times of calculating the channel capacity can be reduced.

In one embodiment, when the K beam combinations with the highest channel capacity are selected from the N beam combinations according to the channel capacity of the target beam combination and the first threshold, the second threshold may be determined according to the channel capacity of the target beam combination and the first threshold, and then the beam combination with the channel capacity greater than the second threshold is selected from the M beam combinations, so that the data amount fed back to the second STA by the first STA may be reduced.

In an embodiment, the channel state information of the target beam combination or the channel state information of the K beam combinations may also be sent to the second STA according to the information acquisition request, and therefore, the second STA may obtain the transmit beam combination of the digital domain beamforming precoding matrix and the analog domain according to the channel state information, where the target beam combination of the transmitted K beam combinations is used as the most preferable beam combination of the first STA and the second STA, and the other K-1 beam combinations are used as backup beam combinations between the first STA and the second STA, and when the target beam combination is blocked by part or all of beam pairs/beam links, resulting in a decrease in quality of the corresponding MIMO link, the first STA and the second STA may synchronously and quickly switch to a backup beam combination stored in advance.

In this embodiment, the first information may include transmission beam information of each of the K beam combinations, where the transmission beam information includes a transmission sector number and a number of a transmission antenna to which the transmission sector belongs, where the number of the transmission antenna may also be represented by a number of a radio frequency chain of the transmission antenna, so as to instruct the second STA to select the transmission sector according to the transmission beam information, and transmit data in the specified transmission beam combination. Each beam combination may also be embodied as a combination of transmit beams or a combination of receive beams for the first STA or the second STA.

In one embodiment, the first information may further include second information indicating a transmission beam or beam pair capable of beam tracking by the second STA in the target beam combination or a transmission beam or beam pair capable of beam tracking by the second STA in each of the K beam combinations, where the transmission beam or beam pair capable of beam tracking by the second STA is determined by the first STA according to the channel state information of the target beam combination or each of the K beam combinations, and the transmission beam or beam pair capable of beam tracking by the second STA refers to a transmission beam or beam pair capable of beam tracking by the second STA independently. Specifically, if one column vector of the effective channel matrix is orthogonal to all other column vectors according to the effective channel matrix of the target beam combination or each of the K beam combinations, the first STA indicates that the channel response of the first STA for a given transmit antenna is orthogonal to the channel responses of other transmit antennas, that is, during beam tracking, adjusting the transmit beam/beam pair corresponding to the given transmit antenna alone does not cause interference to other transmit beam/beam pairs. In addition, when the training sequences transmitted by different transmit antennas/rf chains of the second STA (e.g., the AGC field and/or TRN field of the BRP packet) are orthogonal (e.g., an orthogonal mask is used for the AGC subfield and/or TRN subfield of the BRP packet to orthogonalize the training sequences), or different transmit antennas are orthogonally polarized to perform beam tracking, adjusting the transmit beam/beam pair corresponding to a given transmit antenna individually does not cause interference to other transmit beam/beam pairs. Therefore, the second STA can accurately, flexibly and individually perform beam tracking for the transmission beam or beam pair capable of performing beam tracking independently in the target beam combination without affecting the transmission of other beams or beam pairs not performing beam tracking.

When the link quality of the MIMO link corresponding to one beam combination is degraded, it is possible to accurately perform beam tracking only for a selected beam link (beam pair) whose link quality is degraded at the time of beam tracking, without performing beam tracking for all transmission beams/beam pairs. The second information fed back by the first STA may include, in addition to the transmission beam or beam pair that the second STA can perform beam tracking alone, the number of sectors or the range of sectors that are allowed to be measured in the neighboring sector, where the neighboring sector may be a sector that is adjacent to a spatial dimension such as an azimuth angle (azimuth angle) and an elevation angle (elevation angle) of the transmission beam that can perform beam tracking in the target beam combination or K beam combinations, or may be a sector that is adjacent to a sector number of the transmission beam that can perform beam tracking in the target beam combination or K beam combinations. For example, when the sector range allowing measurement is 3, the second STA can perform beam tracking only in adjacent 3 sectors of the transmission beam or beam pair capable of beam tracking. According to the method for determining the transmission beam/beam pair capable of performing beam tracking alone, the second STA determines the number of neighboring transmission sectors or the sector range allowed to be measured during beam tracking, also according to the channel state information of the beam combination.

A second aspect discloses a STA comprising:

a measuring unit, configured to measure channel state information of N beam combinations, where N is an integer greater than 1;

a communication unit, configured to receive an information acquisition request sent by the second STA, where the information acquisition request includes a first threshold;

a determining unit, configured to determine, according to the channel state information of each beam combination measured by the measuring unit, a beam combination with a largest channel capacity among the N beam combinations as a target beam combination;

a selecting unit, configured to select, according to the channel capacity of the target beam combination determined by the determining unit and a first threshold received by the communication unit, K beam combinations with the highest channel capacity from the N beam combinations, where K is an integer greater than or equal to 1 and smaller than N;

the communication unit is further configured to send the first information of the K beam combinations to the second STA.

In one embodiment, the measurement unit is specifically configured to:

measuring channel coefficients of a beam pair consisting of a transmit sector and a receive sector, the transmit sector being a sector on the second STA and the receive sector being a sector on the STA;

and constructing a channel matrix of each beam combination according to the channel coefficients.

In one embodiment, the determining unit is specifically configured to:

calculating a signal strength gain for each of the beam combinations based on the channel matrix, the signal strength gain being derived from a sum of the modes or a sum of the squares of the modes of the elements in the channel matrix;

selecting M beam combinations from the N beam combinations, wherein the M beam combinations are beam combinations corresponding to the largest M signal strength gains in the N signal strength gains, and M is an integer greater than or equal to 1 and less than N;

calculating a channel capacity for each of the M beam combinations;

and determining the beam combination with the largest channel capacity in the M beam combinations as a target beam combination.

In an embodiment, the selecting, by the determining unit, M beam combinations from the N beam combinations specifically includes:

for each of the N beam combinations, calculating a determinant of a channel matrix for the beam combination;

selecting L beam combinations with the determinant not less than a first preset value from the N beam combinations, wherein L is an integer which is greater than or equal to 1 and less than N;

selecting M beam combinations from the L beam combinations, the M being less than or equal to the L.

As a possible implementation manner, when the STA and the second STA each include only one antenna array, the one antenna array is connected to at least one radio frequency chain, and each radio frequency chain is connected to all antenna elements of the one antenna array, the determining unit is specifically configured to:

determining a signal-to-noise ratio for each of the beam pairs;

selecting P beam pairs from all the beam pairs, wherein P is the larger value of the number of second STA radio frequency chains and the number of STA radio frequency chains, transmitting beams in the P beam pairs respectively belong to different radio frequency chains in the second STA, receiving beams in the P beam pairs respectively belong to different radio frequency chains in the STA, each beam pair in the P beam pairs is the beam pair with the largest signal-to-noise ratio in the first beam pair, and the first beam pair is the whole beam pair between one radio frequency chain of the second STA and one radio frequency chain of the STA;

calculating a first channel capacity of a beam combination formed by the P beam pairs;

selecting a second beam pair with the largest signal-to-noise ratio from the P beam pairs;

setting the signal-to-noise ratio of a third beam pair to 0 to obtain all the set beam pairs, wherein the third beam pair comprises beams of which the number of beams with any one beam in the second beam pair is not more than a second preset value;

selecting I beam pairs from all the set beam pairs, wherein I is equal to P, transmitting beams in the I beam pairs respectively belong to different radio frequency chains in the second STA, receiving beams in the I beam pairs respectively belong to different radio frequency chains in the STA, and each beam pair in the I beam pairs is a beam pair with the largest signal-to-noise ratio in the first beam pair;

calculating a second channel capacity of a beam combination formed by the I beam pairs;

and determining the beam combination corresponding to the larger value of the first channel capacity and the second channel capacity as a target beam combination.

In one embodiment, the selecting unit is specifically configured to:

determining a second threshold according to the channel capacity of the target beam combination and the first threshold;

and selecting the beam combination with the channel capacity larger than the second threshold from the M beam combinations.

In an embodiment, the communication unit is further configured to send the channel state information of the target beam combination or the channel state information of the K beam combinations to the second STA according to the information acquisition request.

In one embodiment, the first information may include transmission beam information of each of the K beam combinations, and the transmission beam information may include a transmission sector number and a number of a transmission antenna to which the transmission sector belongs.

In one embodiment, the first information may further include second information, where the second information is used to indicate a transmission beam or a beam pair capable of beam tracking by the second STA in the target beam combination or the K beam combinations, and/or is used to indicate the number of sectors or a range of sectors allowing measurement in a neighboring sector, where the neighboring sector is a sector adjacent to an azimuth angle, a pitch angle, or a sector number of a transmission beam capable of beam tracking in the target beam combination or the K beam combinations.

A third aspect discloses a STA comprising a processor, a memory, and a transceiver, wherein:

the memory has a set of program codes stored therein, and the processor is configured to call the program codes stored in the memory to perform the following operations:

measuring channel state information of N wave beam combinations, wherein N is an integer greater than 1;

the transceiver is used for receiving an information acquisition request sent by the second STA, and the information acquisition request comprises a first threshold;

the processor is further configured to invoke the program code stored in the memory to perform the following:

determining the beam combination with the largest channel capacity in the N beam combinations as a target beam combination according to the channel state information of each beam combination;

selecting K wave beam combinations with the highest channel capacity from the N wave beam combinations according to the channel capacity of the target wave beam combination and a first threshold, wherein K is an integer which is greater than or equal to 1 and less than N;

and the transceiver is further used for transmitting the first information of the K wave beam combinations to the second STA.

A fourth aspect discloses a computer-readable storage medium storing program code for a STA to perform the information feedback method disclosed in the first aspect or any one of the possible implementations of the first aspect.

In the embodiment of the present invention, after the first STA measures the channel state information of the beam combination, a part of beam combinations is selected from the measured beam combinations according to the first threshold sent by the second STA and the channel state information of each beam combination, and the information of the part of beam combinations is sent to the second STA, without sending all the information of all the beam combinations or all the information of all the measured beam pairs to the second STA, so that the data amount of the information sent by the first STA to the second STA can be greatly reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

FIG. 1 is a schematic diagram of a network architecture according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of another network architecture disclosed in the embodiments of the present invention;

fig. 3 is a schematic structural diagram of an STA according to an embodiment of the present invention;

fig. 4 is a schematic flow chart of an information feedback method according to an embodiment of the present invention;

fig. 5 is a simulation result of channel capacity obtained by the exhaustive beam selection method and the improved beam selection method when M is 1 according to the embodiment of the present invention;

fig. 6 is a simulation result of channel capacity obtained by the exhaustive beam selection method and the improved beam selection method when M is 3 according to the embodiment of the present invention;

fig. 7 is a simulation result of channel capacity obtained by the exhaustive beam selection method and the improved beam selection method when M is 5 according to the embodiment of the present invention;

fig. 8 is a schematic structural diagram of another STA disclosed in the embodiments of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention discloses an information feedback method and an STA (station), which are used for reducing the data volume of information sent by a first STA to a second STA. The following are detailed below.

In order to better understand the information feedback method and the STA disclosed in the embodiments of the present invention, a network architecture used in the embodiments of the present invention is described below. Referring to fig. 1, fig. 1 is a schematic diagram of a network architecture according to an embodiment of the present invention. As shown in fig. 1, the network architecture includes a first STA and a second STA, where the first STA and the second STA respectively include at least two antenna arrays, and each antenna array includes at least two beams (i.e., sectors), where fig. 1 only illustrates a case where the first STA and the second STA both include two antenna arrays, and each antenna array includes eight beams. Each antenna array is connected with only one radio frequency chain, and the antenna arrays of the first STA or the second STA are spaced at a certain distance. Each antenna array generates a codebook-based beam by adjusting the phase of the antenna elements (i.e., analog beamforming training). From the baseband view at both ends of transceiving, two antenna arrays of the first STA and the second STA form low-dimensional Multiple-Input Multiple-Output (MIMO), i.e., 2x2 MIMO.

Taking the architecture shown in fig. 1 as an example, let a channel matrix between antenna array elements of the first STA and the second STA be H, and after the first STA and the second STA complete analog beamforming training, an effective channel matrix between antenna arrays of the first STA and the second STA is H_eff. Defining the codebook of the second STA as C_Tx，j₁And j₂Numbers indicating transmission beams on the 1 st and 2 nd transmission antennas in the second STA, respectively, for example: may be represented by a sector number in the 802.11ad standard, and represents the jth on the 1 st and 2 nd transmit antennas, respectively, in the second STA₁And j₂Antenna Weight Vectors (AWV) for the individual transmit beams. Thus, the analog beamforming encoding matrix F of the second STA_Tx,RFCan be expressed as

Wherein j is₁,j₂＝1,...,|C_Tx|，|C_TxAnd | represents the number of codewords in the transmission codebook. Defining a first STA codebook as C_Rx，i₁And i₂The numbers of the receiving beams on the 1 st and 2 nd receiving antennas in the 1 st and 2 nd first STAs, respectively, can be represented by the sector number in the 802.11ad standard, for example, and respectively represent the ith receiving beam on the 1 st and 2 nd receiving antennas in the 1 st and 2 nd first STAs₁And i₂Antenna weight vectors for the individual receive beams. Thus, the first STA simulates the beamforming encoding matrix W_Rx,RFCan be expressed as

Wherein i₁,i₂＝1,...,|C_Rx|，|C_RxAnd | represents the number of codewords in the receiving codebook. Thus, H_effThe relationship with H is

H_eff(i₁,i₂,j₁,j₂)＝W_Rx,RF(i₁,i₂)HF_Tx,RF(j₁,j₂)

Wherein H_eff(i₁,i₂,j₁,j₂) Indicates that the second STA selection number is i₁And i₂The first STA selects the beam with number j₁And j₂The effective channel matrix in the beam.

Referring to fig. 2, fig. 2 is a schematic diagram of another network architecture according to an embodiment of the present invention. As shown in fig. 2, the network architecture includes a first STA and a second STA, where both the first STA and the second STA only deploy an antenna array, the antenna array includes at least one radio frequency chain, and an output/input signal of each radio frequency chain is connected to all antenna elements of the antenna array in a superposition manner after passing through a phase shifter. By adjusting the phase modulator parameters, the antenna array may generate codebook-based beams. Definition C_TxIs a second STA codebook, and represents the jth thereof₁An antenna weight vector of a second STA, representing the jth₂Antenna weight vectors for a second STA. Thus, the beam matrix F of the second STA_Tx,RFCan be expressed as

Wherein j is₁,j₂＝1,...,|C_TxL. Similarly, define the receiver-side codebook as C_RxAnd represents wherein (i) is₁Antenna weight vector of each receiving end, representing the ith₂Antenna weight vectors for individual receivers. Thus, the first STA beam matrix W_Rx,RFCan be expressed as

Wherein i₁,i₂＝1,...,|C_RxL. Likewise, H_effThe relationship with H is

Wherein, the matrix H_effElement h in (1) is a channel coefficient between the transmission beam and the reception beam.

Based on the above network architecture, please refer to fig. 3, fig. 3 is a schematic structural diagram of an STA according to an embodiment of the present invention. Wherein the STA is a first STA. As shown in fig. 3, the STA includes a processor 301, a memory 302, a transceiver 303, and a bus 304. The processor 301 may be a general purpose Central Processing Unit (CPU), multiple CPUs, a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs in accordance with the present invention. The Memory 302 may be, but is not limited to, a Read-Only Memory (ROM) or other type of static storage device that can store static information and instructions, a Random Access Memory (RAM) or other type of dynamic storage device that can store information and instructions, an Electrically Erasable Programmable Read-Only Memory (EEPROM), a Compact Disc Read-Only Memory (CD-ROM) or other optical Disc storage, optical Disc storage (including Compact Disc, laser Disc, optical Disc, digital versatile Disc, blu-ray Disc, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory 302 may be self-contained and coupled to the processor 301 via a bus 304. The memory 302 may also be integrated with the processor 301. A transceiver 303 for communicating with other devices or communication Networks, such as ethernet, Radio Access Network (RAN), Wireless Local Area Network (WLAN), etc. Bus 304 may include a path that transfers information between the above components.

Wherein, the memory 302 stores a set of program codes, and the processor 301 is configured to call the program codes stored in the memory 302 to perform the following operations:

the transceiver 303 is configured to receive an information acquisition request sent by the second STA and send the information acquisition request to the processor 301, where the information acquisition request includes a first threshold;

processor 301 is also configured to invoke program code stored in memory to perform the following operations:

the transceiver 303 is further configured to transmit the first information of the K beam combinations to the second STA.

As a possible implementation, the way for processor 301 to measure the channel state information of N beam combinations is:

As a possible implementation manner, the processor 301 determines, according to the channel state information of each beam combination, a beam combination with the largest channel capacity among the N beam combinations as a target beam combination in a manner that:

calculating the signal intensity gain of each beam combination according to the channel matrix, wherein the signal intensity gain is obtained according to the sum of the modes or the sum of the squares of the modes of the elements in the channel matrix;

selecting M beam combinations from the N beam combinations, wherein the M beam combinations are beam combinations corresponding to the maximum M signal intensity gains in the N signal intensity gains, and M is an integer greater than or equal to 1 and less than N;

calculating the channel capacity of each beam combination in the M beam combinations;

and determining the beam combination with the largest channel capacity in the M beam combinations as the target beam combination.

As a possible implementation, the processor 301 selects M beam combinations from the N beam combinations by:

calculating a determinant of a channel matrix of a beam combination for each of the N beam combinations;

selecting L wave beam combinations with determinant not less than a first preset value from the N wave beam combinations, wherein L is an integer which is greater than or equal to 1 and less than N;

m beam combinations are selected from the L beam combinations, M being less than or equal to L.

As a possible implementation, when the STA and the second STA only include one antenna array, one antenna array is connected to at least one radio frequency chain, and each radio frequency chain is connected to all antenna elements of one antenna array, the processor 301 determines, according to the channel state information of each beam combination, a beam combination with the largest channel capacity among the N beam combinations as the target beam combination in the following manner:

determining a signal-to-noise ratio for each beam pair;

selecting P wave beam pairs from all wave beam pairs, wherein P is a larger value of the number of radio frequency chains of a second STA and the number of radio frequency chains of the STA, transmitting wave beams in the P wave beam pairs respectively belong to different radio frequency chains in the second STA, receiving wave beams in the P wave beam pairs respectively belong to different radio frequency chains in the STA, each wave beam pair in the P wave beam pairs is a wave beam pair with the largest signal-to-noise ratio in a first wave beam pair, and the first wave beam pair is a whole wave beam pair between one radio frequency chain of the second STA and one radio frequency chain of the STA;

setting the signal-to-noise ratio of a third beam pair to be 0 so as to obtain all the set beam pairs, wherein the third beam pair comprises beams, the number of the beams between the third beam pair and any one beam in the second beam pair is not more than a second preset value;

selecting I wave beam pairs from all the set wave beam pairs, wherein I is equal to P, transmitting wave beams in the I wave beam pairs respectively belong to different radio frequency chains in a second STA, receiving wave beams in the I wave beam pairs respectively belong to different radio frequency chains in the STA, and each wave beam pair in the I wave beam pairs is the wave beam pair with the largest signal-to-noise ratio in a first wave beam pair;

and determining the beam combination corresponding to the larger value of the first channel capacity and the second channel capacity as the target beam combination.

As a possible implementation manner, the processor 301 selects, according to the channel capacity of the target beam combination and the first threshold, the K beam combinations with the highest channel capacity from the N beam combinations as:

a beam combination having a channel capacity greater than a second threshold is selected from the M beam combinations.

As a possible implementation, the transceiver 303 is further configured to send the channel state information of the target beam combination or the channel state information of the K beam combinations to the second STA according to the information acquisition request.

As a possible implementation, the first information may include transmission beam information of each of the K beam combinations, and the transmission beam information includes a transmission sector number and a number of a transmission antenna to which the transmission sector belongs.

As a possible implementation, the first information may further include second information, the second information being used to indicate a transmission beam or a beam pair that can be beam-tracked by the second STA in the target beam combination or the K beam combinations, and/or being used to indicate the number of sectors or a range of sectors that allow measurement in a neighboring sector, which is a sector adjacent to the azimuth angle, the elevation angle, or the sector number of the transmission beam that can be beam-tracked in the target beam combination or the K beam combinations.

In particular implementations, the STA may further include an input device 305 and an output device 306, as one possible implementation, the output device 306 in communication with the processor 301, which may display information in a variety of ways. For example, the output device 306 may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, a projector (projector), or the like. The input device 305 is in communication with the processor 301 and may accept user input in a variety of ways. For example, the input device 305 may be a mouse, a keyboard, a touch screen device, or a sensing device, among others.

Referring to fig. 4 based on the network architecture, fig. 4 is a flowchart of an information feedback method according to an embodiment of the present invention. The information feedback method is described from the perspective of a first STA, and the first STA and a second STA use hybrid beamforming. As shown in fig. 4, the information feedback method may include the following steps.

401. Channel state information for the N beam combinations is measured.

In this embodiment, before the first STA and the second STA perform communication, in order to determine a beam combination for performing communication, the first STA and the second STA need to measure channel state information of N beam combinations through analog beamforming training, for example, the first STA measures a plurality of channel coefficients between all transmitting antennas and all receiving antennas, each channel coefficient corresponds to a beam pair consisting of one transmitting sector and one receiving sector, and then constructs a channel matrix of N beam combinations according to the plurality of channel coefficients. Wherein each beam combination corresponds to an effective channel matrix H_effAnd N is an integer greater than 1. The beam combination includes a set of transmission beams and reception beams, each beam combination corresponds to one MIMO channel matrix, the transmission beams in the transmission beam set respectively belong to different radio frequency chains in the second STA, that is, the number of the transmission beams in the transmission beam set is equal to the number of the radio frequency chains in the second STA, each radio frequency chain in the second STA uniquely includes one transmission beam in the transmission set, and the reception beams in the reception beam set are similar to the definition of the transmission beams in the transmission beam set, which is not described herein again.

In this embodiment, the first STA obtains channel coefficients between each transmit beam and each receive beam between each transmit-receive antenna pair by measuring a preamble or an analog domain beamforming training sequence of a physical layer protocol data unit. Accurately, the analog domain beamforming training can be completed by the beamforming training at the phase of the beam optimization protocol. The first STA may obtain a plurality of accurate channel coefficients by measuring a multi-Sector identification (MID) sub-stage of a Beam optimization protocol stage and/or a multi-Sector identification Capture (MIDC) sub-stage of a Beam Combining (BC) sub-stage.

402. And receiving an information acquisition request which is sent by the second STA and contains the first threshold.

In this embodiment, after the first STA and the second STA complete the analog beamforming training, in order to acquire information of a plurality of beam combinations with high channel capacity and/or further obtain a digital domain beamforming pre-coding matrix using a result of the analog beamforming training, the second STA sends an information acquisition request including the first threshold to the first STA. The second STA obtains information of a plurality of beam combinations with high channel capacity, and except for determining the beam combination with the highest channel capacity as the current MIMO link, other beam combinations with high channel capacity may be used as alternative MIMO links, so as to be used for synchronously and quickly switching to a backup beam combination corresponding to a backup MIMO link after the link quality is reduced due to occlusion in the communication process of the current MIMO link with the first STA. Wherein, the first threshold is an effective number which is larger than 0 and smaller than 1, and represents a relative threshold.

In this embodiment, the information acquisition request sent by the second STA to the first STA is used to instruct the first STA to determine the actually fed back optimal number of transmission beam combinations according to the first threshold. Wherein the first threshold may be a link quality threshold subfield of a beam optimization protocol request field carried within a beam optimization protocol frame, the link quality threshold subfield indicating a proportion of a channel capacity of the MIMO link having a maximum channel capacity. For example, the length of the link quality threshold subfield is 2 bits, and when the link quality threshold field is 0, 1, 2, and 3, respectively, the first STA feeds back all the transmission beam combinations corresponding to the MIMO links having all channel capacities greater than or equal to 1/2, 2/3, 3/4, or 4/5 of the channel capacity of the MIMO link having the largest channel capacity, and/or channel state information corresponding to each transmission beam combination to the second STA. For another example: another implementation manner of the first threshold is a channel capacity threshold field, the length of the channel capacity threshold field is 2 bits, and when the values of the channel capacity threshold field are 3, 2, and 1, respectively, the channel capacity threshold field indicates that the first STA is requested to feed back a beam combination/transmission beam combination with a channel capacity greater than or equal to 90%, 80%, and 70% of the channel capacity of the beam combination with the highest channel capacity; when the value of the channel capacity threshold field is 0, it indicates that the first STA is requested to feed back only the beam combination/transmission beam combination with the highest channel capacity, i.e., to feed back only one optimal beam combination/transmission beam combination. The link quality threshold field or the channel capacity threshold field may be carried in a reserved field within a directional multi-gigabit (DMG) Beam optimization element (DMG Beam optimization element) or in a new EDMG (Enhanced DMG, EDMG) Beam optimization element.

403. And determining the beam combination with the largest channel capacity in the N beam combinations as the target beam combination according to the channel state information of each beam combination.

In this embodiment, after receiving an information acquisition request including a first threshold sent by a second STA, a target beam combination with the largest channel capacity is determined from the N beam combinations according to the channel state information of the beam combination. The received signal strength gain corresponding to each beam combination may be calculated according to the effective channel matrix of each beam combination, M beam combinations may be selected from the N beam combinations according to the received signal strength gain/signal-to-noise ratio, then the channel capacity of each beam combination of the M beam combinations may be calculated, and the beam combination with the largest channel capacity of the M beam combinations may be determined as the target beam combination, so that the number of times of calculating the channel capacity may be reduced. The signal strength gains of the beam combinations are obtained according to the sum of the modes or the sum of the squares of the modes of the elements in the beam combination channel matrix, the M beam combinations are the beam combinations corresponding to the maximum M signal strength gains in the N signal strength gains, and M is an integer greater than or equal to 1 and less than N. Wherein, the calculation of the channel capacity is to perform water injection power and singular value decomposition on the channel matrix.

For example, assume that the second STA has L_TA radio frequency chain, a first STA having L_RA radio frequency chain. When the beam combination adopted by the second STA is the beam combination adopted by the first STA, the (u, v) element for obtaining the effective channel matrix is h_uvThe signal strength gain of the beam combination can be expressed as

Or

For 2x2MIMO, the received signal strength gain corresponding to the beam combination is:

or

For example, assume a 2x2MIMO system, the second STA has 2 transmit antenna arrays, the first STA has 2 receive antenna arrays, each antenna array may be in the form of a phased array antenna array or a directional antenna array, and each antenna array forms a transmit beam or a receive beam in the analog domain. Different transmit antenna arrays or beam combinations of receive antenna arrays correspond to different MIMO links. For the first STA and the second STA, one transmit beam combination or one receive beam combination corresponds to one MIMO link, respectively. Defining the received vector Y as

Where S is a transmit vector, is the effective channel matrix between the first STA and the second STA baseband module, h₁₁，h₁₂，h₂₁，h₂₂Is an element of the effective channel matrix, Z is the noise vector and Y is the sign vector. Defining a Signal to Noise Ratio (SNR) at each receive antenna as

Where the sum defines the average power of the first and second transmit antenna arrays, respectively, is the element variance (either the real part or the variance) of the complex-valued noise vector Z. Assuming then the average signal-to-noise ratio SNR over all receive antenna arrays can be introduced using the definition of the Frobenius matrix norm:

as can be seen from the above equation, when the signal energy is transmitted, it is equal to the total strength of the received signal of the first STA. Maximizing is equivalent to maximizing the average signal-to-noise ratio SNR over all receive antenna arrays when the receiver noise energy is fixed. Therefore, the method for performing the initial beam combination selection according to the received signal strength gain in the present embodiment is equivalent to the method for selecting the beam combination according to the average snr at the receiving antenna array.

In this embodiment, when the first STA and the second STA have the structures as shown in fig. 2, when M beam combinations are selected from the N beam combinations, a determinant of a channel matrix of each beam combination may be calculated, L beam combinations having a determinant not less than a first preset value may be selected from the N beam combinations, that is, the beam combinations having a determinant less than the first preset value are removed from the N beam combinations, and then M beam combinations are selected from the L beam combinations, where L is an integer greater than or equal to 1 and less than N, and M is less than or equal to L. Therefore, the beam combination with smaller channel capacity can be removed by calculating the determinant of the effective channel matrix to narrow the selection range of the beam combination.

In this embodiment, when the first STA and the second STA include only one antenna array, one antenna array is connected to at least one radio frequency chain, and each radio frequency chain is connected to all antenna array elements of the antenna array, that is, the structures of the first STA and the second STA are as shown in fig. 2, when a beam combination with the largest channel capacity in N beam combinations is determined as a target beam combination according to channel state information of each beam combination, a signal-to-noise ratio of each beam pair may be determined first, P beam pairs are selected from all beam pairs, a first channel capacity of the beam combination formed by the P beam pairs is calculated, a second beam pair with the largest signal-to-noise ratio is selected from the P beam pairs, the signal-to-noise ratio of the third beam pair is set to 0 to obtain all beam pairs after setting, I beam pairs are selected from all beam pairs after setting, a second channel capacity of the beam combination formed by the I beam pairs is calculated, and determining the beam combination corresponding to the larger value of the first channel capacity and the second channel capacity as the target beam combination. The method comprises the steps that P is a larger value of the number of radio frequency chains of a first STA and the number of radio frequency chains of a second STA, transmitting beams in P beam pairs respectively belong to different radio frequency chains in the second STA, receiving beams in the P beam pairs respectively belong to different radio frequency chains in the first STA, each beam pair in the P beam pairs is a beam pair with the largest signal to noise ratio in the first beam pair, the first beam pair is a whole beam pair between one radio frequency chain of the second STA and one radio frequency chain of the first STA, a third beam pair comprises beams, the number of the beams between any one beam in the second beam pair is not larger than a second preset value, I is equal to P, the transmitting beams in the I beam pairs respectively belong to different radio frequency chains in the second STA, the receiving beams in the I beam pairs respectively belong to different radio frequency chains in the first STA, and each beam pair in the I beam pairs is a beam pair with the largest signal to noise ratio in the first beam pair.

404. And selecting K wave beam combinations with the highest channel capacity from the N wave beam combinations according to the channel capacity of the target wave beam combination and the first threshold.

In this embodiment, after determining, according to the channel state information of each beam combination, a beam combination with the largest channel capacity among the N beam combinations as a target beam combination, according to the channel capacity of the target beam combination and a first threshold, selecting, from the N beam combinations, K beam combinations with the highest channel capacity, includes determining, first, a second threshold according to the channel capacity of the target beam combination and the first threshold, and then selecting, from the M beam combinations, a beam combination with a channel capacity larger than the second threshold. Wherein K is an integer greater than or equal to 1 and less than N. For example, if the channel capacity of the target beam combination is C_maxIf the value of the first threshold indicator as the relative threshold is a, the second threshold as the absolute threshold is C_thresh＝C_maxA, in this case, the first STA will combine the M beams with a channel capacity greater than or equal to C_threshIs selected as the K beam combinations with the highest channel capacity.

405. And sending the first information of the K wave beam combinations to the second STA.

In this embodiment, the first information may include transmission beam information of each of the K beam combinations, where the transmission beam information includes a transmission sector number and a number of a transmission antenna/radio frequency chain to which the transmission sector belongs, so that the second STA may determine an optimal beam combination and a backup beam combination according to the information of the transmission beams. Since the second STA only needs to know the information of the transmission beam/transmission sector, when the first STA feeds back the transmission beam information of the K beam combinations, it only needs to feed back the information of the transmission beam/transmission sector instead of the reception beam/reception sector, for example: the number of all transmit sectors in a transmit sector combination and the number of their corresponding antenna/radio frequency chains. In one embodiment, the first STA may further send channel state information of the target beam combination or channel state information of the K beam combinations to the second STA according to the information acquisition request, so that the second STA determines the digital domain beamforming precoding matrix of the target beam combination or the K beam combinations. The channel state information may be an effective channel matrix, or a digital domain beamforming feedback matrix obtained according to the effective channel matrix.

In this embodiment, the first information may further include second information, where the second information is used to indicate a transmission beam or beam pair that can be beam-tracked by the second STA in the target beam combination or the K beam combinations, and/or is used to indicate the number of sectors or range of sectors that are allowed to be measured in the neighboring sector, and the transmission beam or beam pair that can be beam-tracked by the second STA is determined by the first STA according to the channel state information of each beam combination in the target beam combination or the K beam combinations. Therefore, when the link quality of the MIMO link corresponding to the beam combination is degraded, the second STA can selectively perform beam tracking only for the beam link (beam pair) whose link quality is degraded at the time of beam tracking. The adjacent sector is a sector adjacent to the azimuth angle, the elevation angle, or the sector number of the transmission beam capable of beam tracking in the target beam combination or the K beam combinations.

Steps 401, 403 and 404 may be performed by the processor 301 in fig. 3 calling the program code stored in the memory 302, and steps 402 and 405 may be performed by the transceiver in fig. 3.

In the information feedback method described in fig. 4, after the first STA measures the channel state information of multiple beam combinations, a part of beam combinations is selected from the measured beam combinations according to the first threshold sent by the second STA and the channel state information of each beam combination, and the information of the part of beam combinations is sent to the second STA, instead of sending all the information of all the beam combinations to the second STA, which can reduce the capacity of the information sent by the first STA to the second STA. This is because, when the first STA and the second STA have multiple antennas/radio frequency chains, and each antenna/radio frequency chain has multiple beams/sectors, the number of beam combinations existing between the first STA and the second STA is large, and the first STA can select the K beam combinations with the highest channel capacity through a complex beam selection algorithm, but the first STA and the second STA cannot predict the MIMO link quality corresponding to the K beam combinations, and by using the information request-information feedback method based on the relative channel capacity threshold of the target beam combination between the first STA and the second STA of this embodiment, while the number of beam combinations fed back is greatly reduced, the link quality/channel capacity of the MIMO link corresponding to the beam combination is considered, so that the second STA can request only those beam combinations satisfying the link quality/channel capacity requirement from the first STA, the beam combination with poor link quality/channel capacity fed back by the first STA is further reduced.

Based on the above network architecture, please refer to fig. 5, fig. 5 is a schematic structural diagram of an STA according to an embodiment of the present invention. Wherein the STA is a first STA. As shown in fig. 5, the STA may include:

a measuring unit 501, configured to measure channel state information of N beam combinations, where N is an integer greater than 1;

a communication unit 502, configured to receive an information acquisition request sent by a second STA, where the information acquisition request includes a first threshold;

a determining unit 503, configured to determine, as a target beam combination, a beam combination with the largest channel capacity among the N beam combinations according to the channel state information of each beam combination measured by the measuring unit 501;

a selecting unit 504, configured to select, according to the channel capacity of the target beam combination determined by the determining unit 503 and the first threshold received by the communication unit 502, K beam combinations with the highest channel capacity from the N beam combinations, where K is an integer greater than or equal to 1 and less than N;

the communication unit 501 is further configured to send the first information of the K beam combinations selected by the selecting unit 504 to the second STA.

As a possible implementation manner, the communication unit 501 is further configured to send the channel state information of the target beam combination or the channel state information of the K beam combinations to the second STA according to the information acquisition request.

In the present embodiment, the STA500 is presented in the form of a functional unit. An "element" may refer to an application-specific integrated circuit (ASIC), a processor and memory that execute one or more software or firmware programs, an integrated logic circuit, and/or other devices that may provide the described functionality. In a simple embodiment, those skilled in the art will appreciate that STA500 may take the form shown in fig. 3. The communication unit 501 may be implemented by the transceiver of fig. 3, and the measurement unit 501, the determination unit 503 and the selection unit 504 may be implemented by the processor and the memory of fig. 3.

For example, when the first STA and the second STA are configured as shown in fig. 1, considering that the transmitting end and the receiving end are disposed in an indoor space of 10m × 8m, the channel matrix H is formed by an LOS component and a first-order wall reflection component. Each linear array comprises 8 antenna units, the number of beams of each array is 16, the distance between two linear arrays of the second STA is 10cm, and the distance between two linear arrays of the first STA is 20 cm. In simulation N₀Ktf, where K is boltzmann's constant, T300K is operating temperature, B2.16 GHz is bandwidth, and F10 dB is noise figure. Due to the fact that strong link attenuation is caused by obstruction, two conditions that an LOS path is not obstructed and the LOS path is obstructed are considered. The second STA is placed at (2,4), the first STA is randomly placed at 10 positions in the space, and the comparison result obtained by averaging the channel capacities obtained by the exhaustive beam selection method and the improved beam selection method is as follows, wherein the simulation result when M is 1 is shown in fig. 6, the simulation result when M is 3 is shown in fig. 7, the simulation result when M is 5 is shown in fig. 8,

from the above simulation results, it can be seen that the channel capacity obtained by the improved beam selection method can obtain a channel capacity close to that obtained by the optimal beam selection (exhaustive beam selection method) regardless of whether the LOS path is blocked. As M increases, the gap between the improved beam selection method and the exhaustive method decreases. The sum of the modes or the sum of squares of the modes is taken as a judgment criterion in the algorithm, the obtained performance difference is small, and the sum of the modes is taken as the criterion for reducing the complexity. Compared with an exhaustive method, the improved beam selection method only needs M times of singular value decomposition and a small amount of summation operation, and the realization complexity is greatly reduced. For example, when exhaustive beam selection is used to find the capacity maximumHigh beam combination needs to traverse all possible beam combinations and adopts transmitting end digital domain precoding and water injection power allocation to calculate channel capacity aiming at each beam combination, multiple singular value decomposition is needed during calculation, complexity is high, and L is provided for a transmitting end_TAn antenna array with L at receiving end_RFor the case of the antenna array, the exhaustive beam selection method needs to complete the sub-singular value decomposition, but the invention only needs M times of singular value decomposition. For 2x2MIMO, when the beamforming codebook contains 16 beam codewords, the complexity ratio (expressed by the number of singular value decompositions) of this embodiment to the exhaustive beam selection method is shown in table 1.

TABLE 12 selection algorithm complexity comparison when x2MIMO codebook contains 16 beams

It should be noted that, although the present embodiment is described by way of example from the perspective of a first STA (receiver of a data frame), when a channel between a second STA (sender of the data frame) and the first STA has reciprocity (reciprocity), since the result of beamforming training does not need to distinguish the first STA or the second STA, the method of the present embodiment may also be performed by the second STA, that is, the first STA and the second STA exchange roles, the second STA performs beamforming training and channel measurement as a receiver of beamforming training in beamforming training before sending the data frame, while the first STA sends an information acquisition request to the second STA, and the second STA performs information feedback described in the present embodiment.

In one embodiment, a computer readable storage medium stores one or more programs, the one or more programs comprising instructions, which when executed by a station, cause the station to perform a method as corresponding to fig. 4.

It should be noted that, for simplicity of description, the above-mentioned embodiments of the method are described as a series of acts or combinations, but those skilled in the art will recognize that the present invention is not limited by the order of acts, as some steps may occur in other orders or concurrently in accordance with the invention. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and modules referred to are not necessarily required by the invention.

Those skilled in the art will appreciate that all or part of the steps in the methods of the above embodiments may be implemented by associated hardware instructed by a program, which may be stored in a computer-readable storage medium, and the storage medium may include: flash disks, Read-Only memories (ROMs), Random Access Memories (RAMs), magnetic or optical disks, and the like.

The information feedback method and the station provided by the embodiment of the present invention are described in detail above, and a specific example is applied in the text to explain the principle and the implementation of the present invention, and the description of the above embodiment is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

An information feedback method, applied to a first station, includes:

measuring channel state information of N wave beam combinations, wherein N is an integer greater than 1;

receiving an information acquisition request sent by the second station, wherein the information acquisition request comprises a first threshold;

determining the beam combination with the largest channel capacity in the N beam combinations as a target beam combination according to the channel state information of each beam combination;

selecting K wave beam combinations with the highest channel capacity from the N wave beam combinations according to the channel capacity of the target wave beam combination and the first threshold, wherein K is an integer which is greater than or equal to 1 and smaller than N;

and sending the first information of the K wave beam combinations to the second station.
The method of claim 1, wherein the measuring channel state information for N beam combinations comprises:

measuring channel coefficients of a beam pair consisting of a transmit sector and a receive sector, the transmit sector being a sector on the second site and the receive sector being a sector on the first site;

and constructing a channel matrix of each beam combination according to the channel coefficients.
The method according to claim 2, wherein the determining the beam combination with the largest channel capacity among the N beam combinations as the target beam combination according to the channel state information of each of the beam combinations comprises:

calculating a signal strength gain for each of the beam combinations based on the channel matrix, the signal strength gain being derived from a sum of the modes or a sum of the squares of the modes of the elements in the channel matrix;

selecting M beam combinations from the N beam combinations, wherein the M beam combinations are beam combinations corresponding to the largest M signal strength gains in the N signal strength gains, and M is an integer greater than or equal to 1 and less than N;

calculating a channel capacity for each of the M beam combinations;

and determining the beam combination with the largest channel capacity in the M beam combinations as a target beam combination.
The method of claim 3, wherein the selecting M beam combinations from the N beam combinations comprises:

for each of the N beam combinations, calculating a determinant of a channel matrix for the beam combination;

selecting L beam combinations with the determinant not less than a first preset value from the N beam combinations, wherein L is an integer which is greater than or equal to 1 and less than N;

selecting M beam combinations from the L beam combinations, the M being less than or equal to the L.
The method of claim 2, wherein when the first station and the second station each include only one antenna array, the one antenna array is connected to at least one radio frequency chain, and each of the radio frequency chains is connected to all antenna elements of the one antenna array, the determining a beam combination with the largest channel capacity among the N beam combinations as the target beam combination according to the channel state information of each of the beam combinations comprises:

determining a signal-to-noise ratio for each of the beam pairs;

selecting P beam pairs from all the beam pairs, wherein P is a larger value of the number of radio frequency chains of a second station and the number of radio frequency chains of a first station, transmitting beams in the P beam pairs respectively belong to different radio frequency chains in the second station, receiving beams in the P beam pairs respectively belong to different radio frequency chains in the first station, each beam pair in the P beam pairs is a beam pair with the largest signal-to-noise ratio in the first beam pair, and the first beam pair is all the beam pairs between one radio frequency chain of the second station and one radio frequency chain of the first station;

calculating a first channel capacity of a beam combination formed by the P beam pairs;

selecting a second beam pair with the largest signal-to-noise ratio from the P beam pairs;

setting the signal-to-noise ratio of a third beam pair to 0 to obtain all the set beam pairs, wherein the third beam pair comprises beams of which the number of beams with any one beam in the second beam pair is not more than a second preset value;

selecting I beam pairs from all the set beam pairs, wherein I is equal to P, transmission beams in the I beam pairs respectively belong to different radio frequency chains in the second station, reception beams in the I beam pairs respectively belong to different radio frequency chains in the first station, and each beam pair in the I beam pairs is a beam pair with the largest signal-to-noise ratio in the first beam pair;

calculating a second channel capacity of a beam combination formed by the I beam pairs;

and determining the beam combination corresponding to the larger value of the first channel capacity and the second channel capacity as a target beam combination.
The method according to claim 3 or 4, wherein said selecting the K beam combinations with the highest channel capacity from the N beam combinations according to the channel capacity of the target beam combination and the first threshold comprises:

determining a second threshold according to the channel capacity of the target beam combination and the first threshold;

and selecting the beam combination with the channel capacity larger than the second threshold from the M beam combinations.
The method according to any one of claims 1-6, further comprising:

and sending the channel state information of the target beam combination or the channel state information of the K beam combinations to the second station according to the information acquisition request.
The method according to any of claims 1-7, wherein the first information comprises transmission beam information for each of the K beam combinations, the transmission beam information comprising a transmission sector number and a number of a transmission antenna to which the transmission sector belongs.
The method according to claim 8, wherein the first information further comprises second information for indicating the transmission beam or beam pair capable of beam tracking by the second station in the target beam combination or the K beam combinations, and/or for indicating the number of sectors or sector ranges allowing measurement in a neighboring sector, which is a sector adjacent to the azimuth angle, elevation angle or sector number of the transmission beam capable of beam tracking in the target beam combination or the K beam combinations.
A station comprising a processor, a memory, and a transceiver, wherein:

the memory has stored therein a set of program code, and the processor is configured to invoke the program code stored in the memory to perform the following operations:

measuring channel state information of N wave beam combinations, wherein N is an integer greater than 1;

the transceiver is configured to receive an information acquisition request sent by the second station, where the information acquisition request includes a first threshold;

the processor is further configured to invoke program code stored in the memory to:

determining the beam combination with the largest channel capacity in the N beam combinations as a target beam combination according to the channel state information of each beam combination;

selecting K wave beam combinations with the highest channel capacity from the N wave beam combinations according to the channel capacity of the target wave beam combination and the first threshold, wherein K is an integer which is greater than or equal to 1 and smaller than N;

the transceiver is further configured to send the first information of the K beam combinations to the second station.
The station of claim 10, wherein the processor measures the channel state information for the N beam combinations by:

measuring channel coefficients of a beam pair consisting of a transmit sector and a receive sector, the transmit sector being a sector on the second site and the receive sector being a sector on the site;

and constructing a channel matrix of each beam combination according to the channel coefficients.
The station of claim 11, wherein the processor determines a beam combination with the largest channel capacity among the N beam combinations as a target beam combination according to the channel state information of each beam combination by:

calculating a signal strength gain for each of the beam combinations based on the channel matrix, the signal strength gain being derived from a sum of the modes or a sum of the squares of the modes of the elements in the channel matrix;

selecting M beam combinations from the N beam combinations, wherein the M beam combinations are beam combinations corresponding to the largest M signal strength gains in the N signal strength gains, and M is an integer greater than or equal to 1 and less than N;

calculating a channel capacity for each of the M beam combinations;

and determining the beam combination with the largest channel capacity in the M beam combinations as a target beam combination.
The station of claim 11, wherein the processor selects M beam combinations from the N beam combinations by:

for each of the N beam combinations, calculating a determinant of a channel matrix for the beam combination;

selecting L beam combinations with the determinant not less than a first preset value from the N beam combinations, wherein L is an integer which is greater than or equal to 1 and less than N;

selecting M beam combinations from the L beam combinations, the M being less than or equal to the L.
The station according to claim 11, wherein when the station and the second station each include only one antenna array, the one antenna array is connected to at least one radio frequency chain, and each of the radio frequency chains is connected to all antenna elements of the one antenna array, the processor determines, according to the channel state information of each of the beam combinations, a beam combination with the largest channel capacity among the N beam combinations as a target beam combination by:

determining a signal-to-noise ratio for each of the beam pairs;

selecting P beam pairs from all the beam pairs, wherein P is the larger value of the number of second site radio frequency chains and the number of site radio frequency chains, transmitting beams in the P beam pairs respectively belong to different radio frequency chains in the second site, receiving beams in the P beam pairs respectively belong to different radio frequency chains in the site, each beam pair in the P beam pairs is the beam pair with the largest signal-to-noise ratio in the first beam pair, and the first beam pair is the whole beam pair between one radio frequency chain of the second site and one radio frequency chain of the site;

calculating a first channel capacity of a beam combination formed by the P beam pairs;

selecting a second beam pair with the largest signal-to-noise ratio from the P beam pairs;

setting the signal-to-noise ratio of a third beam pair to 0 to obtain all the set beam pairs, wherein the third beam pair comprises beams of which the number of beams with any one beam in the second beam pair is not more than a second preset value;

selecting I beam pairs from all the set beam pairs, wherein I is equal to P, transmission beams in the I beam pairs respectively belong to different radio frequency chains in the second site, reception beams in the I beam pairs respectively belong to different radio frequency chains in the site, and each beam pair in the I beam pairs is a beam pair with the largest signal-to-noise ratio in the first beam pair;

calculating a second channel capacity of a beam combination formed by the I beam pairs;

and determining the beam combination corresponding to the larger value of the first channel capacity and the second channel capacity as a target beam combination.
The station according to claim 3 or 4, wherein the processor selects, according to the channel capacity of the target beam combination and the first threshold, the K beam combinations with the highest channel capacity from the N beam combinations by:

determining a second threshold according to the channel capacity of the target beam combination and the first threshold;

and selecting the beam combination with the channel capacity larger than the second threshold from the M beam combinations.
The station according to any of claims 10 to 15, wherein the transceiver is further configured to send the channel state information of the target beam combination or the channel state information of the K beam combinations to the second station according to the information acquisition request.
The station according to any of claims 10-16, wherein the first information comprises transmission beam information for each of the K beam combinations, the transmission beam information comprising a transmission sector number and a number of a transmission antenna to which the transmission sector belongs.
The station according to claim 17, wherein the first information further comprises second information for indicating a transmission beam or beam pair that can be beam-tracked by the second station in the target beam combination or the K beam combinations, and/or for indicating a number of sectors or a range of sectors that allow measurement in a neighboring sector, which is a sector adjacent to an azimuth angle, a pitch angle or a sector number of a transmission beam that can be beam-tracked in the target beam combination or the K beam combinations.