Wireless Local Area Network AP - side MIMO Reception Path Selection Method and Device

Abstract

The present invention discloses a method for selecting a MIMO receiving path at the AP end of a wireless local area network: If there is a data frame to be sent currently, switch to the available transmitting antenna group, send the data and clear the sending status; If there is no data frame to be sent currently, switch to the optimal receiving antenna group, and the AP is in the listening state. If a received data frame is detected, set the receiving status to "1"; If the current receiving status is "1", clear the receiving status and update the terminal uplink service network quality dependence prediction matrix; If the receiving status is "0", or after updating the terminal uplink service network quality dependence prediction matrix, check the training status; If the current training status is "1", traverse all MIMO paths formed by the antenna groups and the terminal, perform AP transmission MIMO path optimization to update the antenna group - terminal MIMO transmission path status matrix, and obtain the updated antenna group receiving MIMO path weight matrix. The present invention also discloses a corresponding device for selecting a MIMO receiving path at the AP end of a wireless local area network.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communication, and more specifically, relates to a method and apparatus for selecting a multiple-input multiple-output (MIMO) receiving path at a wireless local area network access point (AP). Background Art

[0002] With the popularization of mobile wireless terminal products such as mobile phones, tablet computers, and laptop computers, and the development of Internet applications (short videos, live broadcasts, online shopping, online multiplayer games), the requirements of user services for the wireless communication performance of wireless local area network AP products have been continuously improved. Especially for live streaming applications, high requirements are put forward for the stability and capacity of the wireless communication bandwidth of the wireless local area network AP.

[0003] In order to improve the air interface throughput of the wireless local area network, constructing a MIMO wireless link system using multiple transceiver antennas and using the uncorrelation of the wireless link through spatial division multiplexing to construct multiple co-frequency air channels has become a common key technology for improving the air interface transmission capacity of the wireless local area network. In order to realize MIMO spatial division multiplexing data transceiver, at the sending end, it is necessary to perform space-time coding on the data frame according to the MIMO path characteristics to form multiple spatial data streams, and at the receiving end, the data received by each antenna is decoupled by using the transmission matrix formed by the MIMO path characteristics to decompose multiple data streams. Summary of the Invention

[0004] Technical Problem to be Solved

[0005] When the wireless local area network uses MIMO technology to improve the air interface channel capacity, the decoding process of MIMO depends on the uncorrelation of the MIMO path characteristic matrix. When the terminal and the wireless local area network AP device are in certain situations, the MIMO path characteristic matrix shows high correlation, the MIMO path characteristic matrix degenerates, from a full-rank matrix to a rank-deficient matrix. At this time, multiple MIMO data streams cannot be completely decoded, manifested as an increase in the bit error rate, a drop in the negotiated rate level, and a decrease in the air interface throughput.

[0006] In view of the above situation, it is a feasible solution to adopt multiple groups of MIMO antenna switching at the wireless local area network AP end to eliminate MIMO path correlation and improve the MIMO performance in the transceiver direction of the wireless local area network AP for a single terminal.

[0007] In a wireless local area network (WLAN) system, in order to improve the utilization efficiency of the air interface when multiple terminals access, a distributed coordination function (DCF) access management mechanism combined with a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism is usually adopted. That is, each terminal sends service data packets to the WLAN AP according to the air interface status and service requirements. At the WLAN AP side, it is impossible to predict which terminal will initiate air interface communication currently, and it is also impossible to predict which group of MIMO antennas has the best reception performance. Therefore, the existing technology cannot solve the problem of how to select the MIMO antenna group with the best reception performance from multiple groups of MIMO antennas at the WLAN AP side to match the requirements of the services of multiple terminals for the quality of the wireless communication channel.

[0008] Aiming at the problems existing in the prior art, the present invention provides a method for selecting an optimal MIMO receiving antenna group when multiple terminals access in the case of using multiple groups of MIMO antennas at the AP side. By using the method of the present invention, the optimal MIMO antenna group of the system is selected to optimize the reception performance at the AP side and improve the transmission efficiency of the air interface.

[0009] To achieve the above object, according to one aspect of the present invention, a method for selecting a MIMO receiving path at a WLAN AP side is provided, including the following steps:

[0010] If there is a data frame to be sent currently, switch to the available transmitting antenna group, send the data by using the available transmitting antenna group and clear the sending status; if there is no data frame to be sent currently, switch to the optimal receiving antenna group, and the AP is in a listening state. If a received data frame is detected, set the receiving status to "1".

[0011] If the current receiving status is "1", clear the receiving status and update the service weight of the corresponding terminal in the terminal uplink service network quality dependence prediction matrix; if the receiving status is "0", or after updating the service weight of the corresponding terminal in the terminal uplink service network quality dependence prediction matrix, check the training status.

[0012] If the current training status is "1", traverse all MIMO paths formed by antenna groups and terminals, perform AP transmission MIMO path optimization to update the antenna group - terminal MIMO transmission path status matrix, and perform AP reception MIMO path weight calculation to obtain an updated antenna group reception MIMO path weight matrix.

[0013] In one embodiment of the present invention, before determining whether there is a data frame to be sent currently, it further includes: determining whether the information processing and decision-making module is executed for the first time. If it is "yes", initialize the key data structures and states.

[0014] In one embodiment of the present invention, the initialization of the key data structures and states includes: constructing and initializing the data elements in the antenna group - terminal MIMO transmission path state matrix, the terminal uplink service network quality dependence estimation matrix, and the antenna group received MIMO path weight matrix, where:

[0015] The antenna group - terminal MIMO transmission path state matrix is an m-row and n-column matrix composed of m antenna groups and n terminals, where m≥2, the number of m is the same as the number of MIMO antenna groups owned by the AP, the number of n is the same as the maximum number of terminals that the AP can access. The data in each row represents the MIMO path state of 1 antenna group and all terminals, and the data in each column represents the MIMO path state of 1 terminal and all antenna groups, where as xy represents the state of the MIMO path formed by the x-th antenna group and the y-th terminal;

[0016] The terminal uplink service network quality dependence estimation matrix is a one-dimensional matrix with n rows composed of n terminals, where w x represents the estimated value of the dependence of the current service of the x-th terminal on the network quality. The larger the value, the higher the dependence degree of the service on the network quality;

[0017] The antenna group received MIMO path weight matrix is a one-dimensional matrix with m rows composed of m antenna groups, where m≥2, aw x represents the total weight of the MIMO paths formed by the x-th antenna group and all terminals for the expected service network quality. The larger the value, the more terminals and service requirements the antenna group can match in the system.

[0018] In one embodiment of the present invention, if there is a downlink data frame to be sent currently, switching to the available transmitting antenna group includes: extracting the physical address of the target terminal from the data frame, finding the column corresponding to the target terminal in the antenna group - terminal MIMO transmission path state matrix, and finding the first available element in this column of data. The antenna group corresponding to the row number of this element is the available MIMO transmitting antenna group, and drive the antenna selection module to switch the corresponding antenna group to be connected to the radio frequency circuit module to achieve the switching of the antenna group.

[0019] In one embodiment of the present invention, if the current state is the receiving state, the receiving state is cleared, and the service weight of the corresponding terminal in the uplink service network quality dependence prediction matrix of the terminal is updated. Specifically, when the AP receives the uplink service data frame sent by the terminal, the communication characteristics of the uplink service data frame are extracted, the dependence degree of the terminal service on the network quality is estimated, and the service weight of the corresponding terminal in the uplink service network quality dependence prediction matrix of the terminal is updated.

[0020] In one embodiment of the present invention, if the current state is the training state, all MIMO paths formed by all antenna groups and terminals are traversed to perform AP transmission MIMO path optimization and update the antenna group-terminal MIMO transmission path status matrix. Specifically, by using a traversal method, training frames are sent to each MIMO path formed by each antenna group and each associated terminal, the MIMO correlation status of each MIMO antenna group-terminal path is obtained from the response frame, and the corresponding data element in the antenna group-terminal MIMO transmission path status matrix is updated.

[0021] In one embodiment of the present invention, the AP receives MIMO path weight calculation is performed to obtain an updated antenna group receive MIMO path weight matrix. Specifically, through the current AP transmission MIMO path situation and the dependence estimation of the terminal uplink service on the network quality, the probability weight that each MIMO receive path formed by each antenna group at the AP end meets the network quality requirements of all current terminal uplink services is calculated, and the data element of the antenna group receive MIMO path weight matrix is updated.

[0022] In one embodiment of the present invention, the initialization of the key data structure and status is specifically implemented as follows:

[0023] Construct an m-row n-column antenna group-terminal MIMO transmission path status matrix composed of m antenna groups and n groups of terminals, where m≥2 and n is the maximum number of accessible terminals, for recording the transmission MIMO path status from each antenna group to each terminal; the matrix is initialized and assigned values, the first row is all 1, and the other rows are all 0, that is, by default, all MIMO paths formed by the first antenna group and all n terminals are available transmission paths, where 1 represents an available transmission path and 0 represents an unavailable path;

[0024] Construct an n-row 1-column terminal uplink service network quality dependence prediction matrix composed of n groups of terminals, for recording the user service weight of each terminal, and the initialization assignment is all 0, that is, the service weights of the initial terminals are all 0, and 0 is the minimum weight;

[0025] Construct an antenna group receiving MIMO path weight matrix with m rows and 1 column composed of m antenna groups, which is used to store the receiving MIMO path weights of each antenna group. Initialize the assignment and set all of them to 0. 0 is the minimum weight, that is, by default, there is no suitable receiving MIMO path in the initial state.

[0026] In an embodiment of the present invention, after sending the downlink data frame, clear the sending state and switch to the optimal receiving antenna group, so that the AP performs air interface listening and receives the uplink data frame of the terminal with the system optimal receiving antenna group. The specific implementation includes:

[0027] Scan the antenna group receiving MIMO path weight matrix, find the row corresponding to the maximum weight from it. The antenna group corresponding to this row is the system optimal receiving antenna group. Using the receiving MIMO path formed by this antenna group can meet the requirements of the system's maximum air interface transmission efficiency; if all weights are 0, it indicates that there is no accessed terminal or the terminal does not send data. At this time, an antenna group corresponding to any row in the antenna group receiving MIMO path weight matrix can be selected; send a control signal to the antenna group selection module to select and enable the antenna group represented by this row number.

[0028] In an embodiment of the present invention, if the current is the receiving state, clear the receiving state and update the service weight of the corresponding terminal in the terminal uplink service network quality dependence prediction matrix. The specific implementation includes:

[0029] After the AP receives the service type wireless data frame sent by the jth terminal, calculate and update the dependence degree of the service of the jth terminal on the MIMO path quality in the terminal uplink service network quality dependence prediction matrix, and calculate and iteratively update the weight data in the terminal uplink service network quality dependence prediction matrix after each received service frame;

[0030] Parse the MAC layer characteristic information data of the service data frame, and calculate the dependence degree of the current data frame on the wireless network transmission ability according to the data characteristics, frame type, service type, and QoS information of the MAC layer, and convert it into the dependence degree of the service on the MIMO path quality. The larger the value, the higher the dependence of the service on the MIMO path quality;

[0031] The dependence degrees of all service data frames sent by the jth terminal on the wireless network transmission ability can be regarded as a series of input excitation sequences f(X0, X1, X2,...) of the wireless network transmission quality requirements superimposed with noise and perturbations from the 0th moment to an infinitely long moment. x0 represents the value at the 0th moment, x1 represents the value at the 0 + 1th moment, and so on;

[0032] Perform one-dimensional convolutional filtering on the input excitation sequence, and extract the dependence p(n) of the terminal service on the communication bandwidth from it. The larger p(n) is, the stronger the dependence of the service on the network MIMO path quality;

[0033] Use the calculated dependence p(n) of the terminal service on the MIMO path to replace the data in the j-th row of the terminal uplink service network quality dependence prediction matrix.

[0034] In an embodiment of the present invention, if it is in the training state currently, traverse all MIMO paths formed by antenna groups and terminals, perform AP transmission MIMO path optimization, and update the antenna group-terminal MIMO transmission path status matrix. The specific implementation includes:

[0035] When the AP performs timed iteration or a new terminal is associated with the AP, bring in the antenna group number i and terminal number j that need to be scanned this time, and obtain the MIMO path status between the i-th antenna group and the j-th terminal;

[0036] Switch the antenna group to the i-th group;

[0037] Send a training frame to the j-th terminal through the MIMO path formed by the i-th antenna group and the j-th terminal, and receive the feedback response frame of the j-th terminal;

[0038] Extract the CSI information of the current MIMO path and the current MIMO path correlation from the response frame. When the MIMO path correlation is greater than the threshold, it indicates that the performance of the MIMO path formed by the i-th antenna group and the j-th terminal is poor. At this time, set the element in the i-th row and j-th column of the antenna group-terminal MIMO transmission path status matrix to 0, otherwise set it to 1. One terminal may form available MIMO paths with multiple antenna groups; 1 represents an available transmission path, and 0 represents an unavailable path;

[0039] Update the values of i and j to prepare for obtaining the next path status;

[0040] Return (i, j) to complete the acquisition of the current path status.

[0041] In an embodiment of the present invention, perform AP reception MIMO path weight calculation to obtain an updated antenna group reception MIMO path weight matrix. The specific implementation includes:

[0042] Using the data of the antenna group - terminal MIMO transmission path status matrix and the terminal uplink service network quality prediction matrix, calculate the sum of probabilities of satisfying all services for each MIMO path formed by each antenna group and all terminals, that is, the weight; perform matrix multiplication using the antenna group - terminal MIMO transmission path status matrix and the terminal uplink service network quality prediction matrix to obtain a new antenna group received MIMO path weight matrix. The antenna group received MIMO path weight matrix is a one-dimensional matrix with m rows, and each row represents the weight of the antenna group received MIMO path corresponding to the row number. Among them, the maximum value AWmax is the antenna group of the current optimal received MIMO path, and this antenna group can meet the quality requirements of the uplink network for the services of all terminals with the highest probability.

[0043] According to another aspect of the present invention, there is also provided a wireless local area network AP - side MIMO receiving path selection device, including at least one processor and a memory. The at least one processor and the memory are connected through a data bus. The memory stores instructions executable by the at least one processor, and after being executed by the processor, the instructions are used to complete the wireless local area network AP - side MIMO receiving path selection method described above.

[0044] Generally speaking, compared with the prior art through the above - mentioned technical solutions conceived by the present invention, the following beneficial effects are achieved:

[0045] 1. The present invention provides a method for selecting the optimal received antenna group in a multi - antenna group of a wireless local area network AP - side;

[0046] 2. The present invention provides a receiving MIMO path selection method based on service weights. When multiple terminals access in an AP device with multiple MIMO antenna groups, it is a method for selecting the optimal received antenna of the AP system, and using this method can meet the performance requirements of the uplink services carried by each terminal for the air - interface communication with the highest probability;

[0047] 3. The method provided by the present invention can also realize the selection of the optimal MIMO receiving path at the AP - side when there is only a single wireless local area network terminal in the system;

[0048] 4. The method used in the present invention does not change the communication mode of the wireless local area network and does not require modification of the wireless local area network terminal. It has the advantages of better comprehensive performance, wider application range, and no need for terminal adaptation. Brief Description of the Drawings

[0049] Figure 1 It is a hardware block diagram of multiple groups of MIMO antennas at the wireless local area network AP - side in an embodiment of the present invention;

[0050] Figure 2 It is a process of an information processing and decision - making module in an embodiment of the present invention;

[0051] Figure 3 is the key sub-module of the information processing and decision-making module in the embodiment of the present invention;

[0052] Figure 4 is the process of the data initialization module in the embodiment of the present invention;

[0053] Figure 5 is the process of the AP receiving antenna decision module in the embodiment of the present invention;

[0054] Figure 6 is the process of the terminal uplink service network path quality dependence estimation module in the embodiment of the present invention;

[0055] Figure 7 is the process of the AP transmitting MIMO path optimization module in the embodiment of the present invention;

[0056] Figure 8 is the process of the AP receiving MIMO path weight calculation module in the embodiment of the present invention;

[0057] Figure 9 is the flow chart of the training timer interrupt in the embodiment of the present invention;

[0058] Figure 10 is Embodiment 1 in the embodiment of the present invention;

[0059] Figure 11 is Embodiment 2 in the embodiment of the present invention. Specific implementation manners

[0060] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0061] The present invention is mainly applied to the scenario where wireless local area network (WLAN) AP products use multiple groups of MIMO antennas to improve the performance of the MIMO air interface link. The product forms mainly include WLAN APs and other products with WLAN AP functions, such as WLAN gateways and other products.

[0062] The technical solution adopted to solve this technical problem is:

[0063] 1) Hardware carrier:

[0064] The technical solution of the present invention adopts the following 100 hardware carriers and applies them to the AP side of the wireless local area network. The system block diagram of the 100 hardware carriers is shown in Figure 1, including:

[0065] 200 Information processing and decision-making module: Composed of a CPU and a storage unit, it is used to execute the optimization algorithm for the MIMO paths of sending and receiving, store the calculation results, and drive the antenna selection module to perform MIMO path selection.

[0066] 300 Wireless local area network baseband chip module: Connected to the radio frequency circuit module, it realizes all the logical functions of the LOWMAC layer and PHY layer of the wireless local area network and the channel encoding and decoding functions.

[0067] 400 Radio frequency circuit module: Composed of a radio frequency transmitting circuit, a radio frequency receiving circuit, and a TR switch. The radio frequency transmitting end output by the wireless local area network baseband chip is connected to the radio frequency transmitting circuit, the radio frequency receiving end of the wireless local area network baseband chip is connected to the radio frequency receiving circuit, the transceiver control end of the wireless local area network baseband chip is connected to the TR switch circuit, and the common end of the TR switch circuit is connected to the antenna group selection module; Radio frequency transceiver selection, signal amplification, filtering, and matching are completed in the radio frequency circuit module.

[0068] 500 Antenna selection module: Composed of multiple groups of radio frequency switches, each group of radio frequency switches controls at least 2 antennas, and is used to select different MIMO paths.

[0069] 600 m (m≥2) MIMO antenna groups: Each antenna group has at least 2 antennas, and at least one antenna is not shared with other antenna groups, so as to construct different MIMO paths for the air interface from the wireless local area network AP to the terminal.

[0070] 2) Key data structures:

[0071] The present invention uses the following data structures, data registers, and status registers to store data for information processing and decision-making:

[0072] 3 matrix data structures are used to store data;

[0073] 1 data register, which is used to store the training interval time so as to periodically start MIMO path training;

[0074] 3 status registers, which are used to store the sending, receiving status, and training status. The descriptions of the above data are as follows:

[0075] Antenna set - The terminal MIMO transmission path status matrix, briefly denoted as the AS matrix, as shown in Formula 1, is an m (m≥2) - row and n - column matrix composed of m antenna sets and n terminals. The number of m is the same as the number of MIMO antenna sets owned by the AP, and the number of n is the same as the maximum number of terminals that the AP can access. The data in each row represents the MIMO path status of 1 antenna set and all terminals, and the data in each column represents the MIMO path status of 1 terminal and all antenna sets. Among them, as xy represents the status of the MIMO path formed by the x - th antenna set and the y - th terminal. The status of 1 indicates available, and the status of 0 indicates a non - optimal MIMO path.

[0076]

[0077] Terminal uplink service network quality dependence estimation matrix, briefly denoted as the SW matrix, as shown in Formula 2, is a one - dimensional matrix with n rows composed of n terminals. Among them, w x represents the estimated value of the dependence of the x - th terminal's current service on network quality. The larger the value, the higher the degree of dependence of the service on network quality. To unify the dependence scale, this dependence value is normalized to a value between 0 - 100. 0 represents the lowest, and 100 represents the highest.

[0078]

[0079] Antenna set received MIMO path weight matrix, briefly denoted as the AW matrix, as shown in Formula 3, is a one - dimensional matrix with m rows composed of m (m≥2) antenna sets. Among them, aw x represents the total matching weight of the MIMO paths formed by the x - th antenna set and all terminals for the expected service network quality. The larger the value, the more terminals and service requirements the antenna set can match in the system. This matrix is equal to the result of multiplying matrix AS and matrix SW.

[0080]

[0081] Data register: Training timer, stores the interval time between two path trainings. Each time a training timer interrupt occurs, this value decreases. When it decreases to "0", it means the training period has been reached.

[0082] Status register 1: Transmission status. When the system needs to send a data frame to the terminal, it is set to "1" by the system main program, and the initial state is "0".

[0083] Status register 2: Reception status. When the system receives a data frame sent by the terminal, it is set to "1" by the system main program, and the initial state is "0".

[0084] Status register 3: Training status. When it is "1", path training is started; when it is "0", path training is not performed.

[0085] The present invention discloses a method for selecting a MIMO receiving path at the AP side of a wireless local area network, including the following steps:

[0086] If there is a data frame to be sent currently, switch to the available transmitting antenna group, use the available transmitting antenna group to send data and clear the sending status; if there is no data frame to be sent currently, switch to the optimal receiving antenna group, the AP is in the listening state, if a received data frame is detected, set the receiving status to "1";

[0087] If the current receiving status is "1", clear the receiving status and update the service weight of the corresponding terminal in the terminal uplink service network quality dependence prediction matrix; if the receiving status is "0", or after updating the service weight of the corresponding terminal in the terminal uplink service network quality dependence prediction matrix, check the training status;

[0088] If the current training status is "1", traverse all MIMO paths formed by antenna groups and terminals, perform AP transmitting MIMO path optimization to update the antenna group-terminal MIMO transmitting path status matrix, and perform AP receiving MIMO path weight calculation to obtain the updated antenna group receiving MIMO path weight matrix.

[0089] 3) The execution logic and process of the main process of the 200 information processing and decision-making module are as follows:

[0090] Embed the 200 information processing and decision-making module in the main process of the wireless local area network AP and call it in the main loop to implement operations such as MIMO path status collection, service weight calculation, and receiving antenna selection. The specific logic and process are shown in Figure 2 , and the execution process is as follows:

[0091] 201 Judge whether the information processing and decision-making module is executed for the first time. If it is "yes", call the 202 data initialization module; otherwise, jump to 203.

[0092] 202 Execute the call to the data initialization module to complete the initialization of key data structures and statuses; after completion, execute 203.

[0093] 203 Judge whether there is data to be sent currently. If the sending status is 1, judge it as "yes" and execute 204 to switch to the available transmitting antenna group; otherwise, jump to 206.

[0094] 204 extracts the target terminal's physical address (Media Access Control Address) from the data frame, finds the column corresponding to the target terminal in the AS matrix, and locates the first element with a value of 1 in this column of data. The antenna group corresponding to the row number of this element is the available MIMO transmit antenna group. Drive the 500 antenna selection module to switch the corresponding antenna group to connect to the 400 radio frequency circuit module to achieve the antenna group switch. After completion, execute 205.

[0095] 205 sends data and sets the send status to 0; after returning from 205, execute 206.

[0096] 206 calls the receive antenna decision module to switch to the optimal receive antenna group. The AP is in the listening state. After completion, execute 207.

[0097] 207 checks the receive status. If the receive status is 1, the judgment is "yes", and execute 208; otherwise, jump to 209.

[0098] 208 sets the receive status to 0, calls the terminal uplink service network path quality dependence prediction module to update the service weight of the corresponding terminal in the SW matrix. After completion, execute 209.

[0099] 209 checks the training status. If the training status is 1 (see the training timer interrupt process for the setting of the training status), the judgment result is "yes", execute 210, otherwise jump to 212.

[0100] 210 traverses all MIMO paths formed by antenna groups and terminals, calls the AP transmit MIMO path optimization module to update the AS matrix. After completion, execute 211.

[0101] 211 calls the AP receive MIMO path weight calculation module to obtain the updated AW matrix. After completion, execute 212.

[0102] 212 returns from the 200 information processing and decision module to the main process of the wireless local area network AP to perform other operations.

[0103] 4) Key sub - modules of the information processing and decision module, see Figure 3 ,including:

[0104] 202 data initialization module: This sub - module constructs and initializes the data elements in the AS matrix, SW matrix, and AW matrix.

[0105] 206 AP receive antenna decision module: This module realizes the selection of the receive antenna group and drives the hardware circuit to achieve the antenna group switch.

[0106] 208 Uplink Service Network Quality Dependency Estimation Module: This module is called when the AP receives the uplink service data frame sent by the terminal. It extracts the communication characteristics of the uplink service data frame, estimates the degree of dependence of the terminal service on the network quality, and updates the data element corresponding to the terminal in the SW matrix.

[0107] 210 AP Transmitting MIMO Path Optimization Module: Using a traversal method, it sends training frames to the MIMO paths formed by each antenna group and each associated terminal, obtains the MIMO correlation status of each MIMO antenna group-terminal path from the response frames, and updates the corresponding data element in the AS matrix.

[0108] 211 AP Receiving MIMO Path Weight Calculation Module: Based on the current AP transmitting MIMO path situation and the estimation of the dependence of the terminal uplink service on the network quality, it calculates the probability weight that the MIMO receiving path formed by each antenna group at the AP end meets the network quality requirements of all current terminal uplink services, and updates the data element of the AW matrix.

[0109] 220 Training Timer Interrupt Module: It realizes setting the training status according to the preset time.

[0110] 5) The logic and process of the 202 Data Initialization Sub-module are shown in Figure 4

[0111] The 202 module completes the initialization of the key data structures, as described below:

[0112] 202_1 Starts the data initialization module.

[0113] 202_2 Constructs an m×n AS matrix composed of m (m≥2) antenna groups and n groups (the maximum number of accessible terminals) of terminals, which is used to record the transmitting MIMO path status from each antenna group to each terminal; the matrix is initialized and assigned values. All elements in the first row are 1 (available transmitting paths), and all elements in other rows are 0 (non-optimal), that is, by default, all MIMO paths formed by the first antenna group and all n terminals are available transmitting paths.

[0114] 202_3 Constructs an n×1 SW matrix composed of n groups (the maximum number of accessible terminals) of terminals, which is used to record the user service weights of each terminal, and the initialization assignment is all 0, that is, the service weights of the initial terminals are all 0 (minimum weight).

[0115] 202_4 Constructs an m×1 AW matrix composed of m (m≥2) antenna groups, which is used to store the receiving MIMO path weights of each antenna group. The initialization assignment is all set to 0 (minimum weight), that is, by default, there is no suitable receiving MIMO path in the initial state.

[0116] 202_5 Initialize the training timer, start the training timer, and the training timer begins; set the send status, receive status, and training status all to "0".

[0117] 202_6 Return.

[0118] 6) Logic and process of the 206AP receive antenna decision module, see Figure 5

[0119] 206_1 When the AP needs to select the optimal receive antenna group, this module is called to implement the process of switching the antenna group to the system-optimal receive antenna group.

[0120] 206_2 Scan the AW matrix, find the row corresponding to the maximum weight from it, and the antenna group corresponding to this row is the system-optimal receive antenna group. Using the receive MIMO path formed by this antenna group can meet the requirements of the system's maximum air interface transmission efficiency; if all weights are 0, it indicates that there are no connected terminals or the terminals are not sending data. At this time, any row in the AW matrix can be selected.

[0121] 206_3 Send a control signal to the 500 antenna group selection module to select the antenna group represented by this row number.

[0122] 206_4 After completing the operation, return.

[0123] 7) Logic and process of the 208 terminal uplink service network quality dependence estimation module, see Figure 6

[0124] After the AP receives the service-type wireless data frame sent by the jth terminal, this module is called to calculate and update the dependence degree of the service of the jth terminal on the MIMO path quality in the SW matrix. This module needs to be called every time a service frame is received and iteratively update the weight data in the SW matrix.

[0125] 208_1 Bring the MAC layer packet feature information of the wireless data frame sent by the jth terminal into this module.

[0126] 208_2 Parse the MAC layer feature information data, calculate the dependence degree of the current data frame on the wireless network transmission ability according to the MAC data features, frame type, service type, QoS information, etc., which can be converted into the dependence degree of the service on the MIMO path quality. The larger the value, the higher the dependence of the service on the MIMO path quality. Normalize this value to a value between 0 - 100.

[0127] The degree of dependence of all service data frames sent by the j-th terminal on the wireless network transmission capacity can be regarded as a series of input excitation sequences f(X0, X1, X2,......) of wireless network transmission quality requirements superimposed with noise and perturbations from the 0th moment to an infinitely long moment. x0 represents the value at the 0th moment, x1 represents the value at the 0 + 1 moment, and so on.

[0128] Perform a one-dimensional convolutional filtering on this input excitation sequence to extract the dependence p(n) of the terminal service on the communication bandwidth. The larger p(n) is, the stronger the dependence of the service on the network MIMO path quality.

[0129] Use the calculated dependence p(n) of the terminal service on the MIMO path to replace the data in the j-th row of the SW matrix.

[0130] Return.

[0131] 8) The logic and process of the MIMO path optimization module sent by the 210 AP are shown in Figure 7

[0132] The 210 module completes the status check of an antenna MIMO path, as described below:

[0133] When the AP performs timed iteration or a new terminal is associated with the AP, when this module is called, the antenna group number i to be scanned this time and the terminal number j are brought in to obtain the MIMO path status between the i-th antenna group and the j-th terminal.

[0134] Switch the antenna group to the i-th group.

[0135] Send a training frame to the j-th terminal through the MIMO path formed by the i-th antenna group and the j-th terminal, and receive the feedback response frame from the j-th terminal.

[0136] Extract the CSI information of the current MIMO path from the response frame and extract the current MIMO path correlation. When the MIMO path correlation is greater than the threshold, it indicates that the performance of the MIMO path formed by the i-th antenna group and the j-th terminal is poor. At this time, set the i-th row and j-th column of the AS matrix to 0 (unavailable path), otherwise set it to 1 (available transmission path). One terminal may form available MIMO paths with multiple antenna groups.

[0137] Update the values of i and j to prepare for the next path status acquisition.

[0138] Return (i, j) to complete the collection of the current MIMO transmission path status.

[0139] 9) The logic and process of the 211AP receiving MIMO path weight calculation module are shown in Figure 8

[0140] The 211 module uses the data of the AS (antenna group - terminal MIMO transmission path status matrix) matrix and the SW (terminal uplink service network quality prediction matrix) matrix to calculate the probability sum of each MIMO path formed by each antenna group and all terminals that meets all services, that is, the weight; perform matrix multiplication on the AS matrix and the SW matrix, AS*SW to obtain a new matrix AW. The AW matrix is a one-dimensional matrix with m rows (the same as the number of antenna groups), and each row represents the weight of the receiving MIMO path of the antenna group corresponding to the row number (the probability of meeting the network quality requirements of all terminal services). The maximum value AWmax is the antenna group of the current optimal receiving MIMO path, and this antenna group can meet the quality requirements of the uplink network for all terminal services with the highest probability.

[0141] 10) The process of the 220 training timer interrupt module is shown in Figure 9 。

[0142] 220_1 When a timer interrupt occurs in the system, this training timer interrupt module is called.

[0143] 220_2 Check the training status. If the training status is 1, it indicates that the previous training has not been completed yet, and directly jump to 220_6; if the training status = 0, execute 220_3.

[0144] 220_3 Decrease the training timer by 1 and execute 220_4.

[0145] 220_4 Determine whether the training timer is "0". If it is "0", execute 220_5; otherwise, jump to 220_6.

[0146] 220_5 Restore the initial value of the training timer and set the training status to "1"; execute 220_6.

[0147] 220_6 Interrupt return.

[0148] The method of the present invention will be described below in conjunction with two specific embodiments.

[0149] Embodiment 1 is shown in Figure 10, a wireless local area network (WLAN) AP with four antennas, named A-1, A-2, B-1, and B-2 respectively. The four antennas form two groups of MIMO antenna groups, the first antenna group (A-1, A-2) and the second antenna group (B-1, B-2). The first antenna group and the second antenna group respectively form different MIMO low-correlation coverage areas. Within the coverage area, the MIMO path formed by the AP antenna group and the terminal has low correlation, and an ideal air interface throughput can be obtained. Outside the coverage area, the MIMO path formed by the AP antenna group and the terminal has high correlation, and MIMO diversity gain cannot be obtained, resulting in a low negotiation rate and a low air interface throughput. Among them, there is a part of the area that is the overlapping area covered by the first and second antenna groups. Within the overlapping coverage area, the terminal can form a low-correlation air interface MIMO path with either the first antenna group or the second antenna group of the WLAN AP. At this time, no matter which antenna group is used to construct the MIMO path, an ideal air interface throughput can be obtained.

[0150] Example 2 is shown in Figure 11 , a wireless local area network (WLAN) AP with three antennas, named A, B, and C respectively. Among them, antenna A is a common antenna, antenna A-B forms the first antenna group, and antenna A-C forms the second antenna group. The first antenna group and the second antenna group each form a MIMO low-correlation coverage area. Terminals within the area can form high-quality MIMO channels with the corresponding antenna groups. There is an overlapping area between the low-correlation coverage areas of the first antenna group and the second antenna group. When the terminal is within the overlapping coverage area, it can form low-correlation MIMO paths with both the first antenna group and the second antenna group, and an ideal air interface throughput can be obtained.

[0151] To introduce the working principle of the present invention, assume that in the above two embodiments, there are three terminals, forming a wireless communication scenario with the WLAN AP in the embodiments. The three WLAN terminals in the above system are: Terminal-A, Terminal-B, and Terminal-C. Assume the distribution of the three terminals is as follows:

[0152] 1) Terminal-A is in the MIMO low-correlation coverage area of the first antenna group;

[0153] 2) Terminal-B is in the MIMO low-correlation overlapping area of the first and second antenna groups, that is, it can form low-correlation MIMO channels with both the A antenna group and the B antenna group;

[0154] 3) Terminal-C is in the MIMO low-correlation coverage area of the second antenna group;

[0155] The information collection and decision-making process using the present invention:

[0156] 1) Data initialization, constructing and initializing the AS matrix, SW matrix, and AW matrix, see Equations 4, 5, and 6;

[0157] 2) Collection of MIMO path status at the wireless LAN AP side

[0158]

[0159] Perform MIMO path optimization at the wireless LAN AP side. Send training frame queues through the first and second antenna groups respectively, traverse all MIMO paths formed by all antenna groups and all terminals, obtain the correlation status of the MIMO paths constructed by the first and second antenna groups respectively with all terminals in the system. Those with a correlation higher than the threshold are marked as 0, and those lower than the threshold are marked as 1. The data in Equation 4 can be updated, and the updated value of AS is shown in Equation 7. Due to the mobility of the terminals, it is necessary to perform MIMO path traversal operations regularly to maintain tracking of the current status.

[0160]

[0161]

[0162] 3) Estimation of the dependence of the terminal uplink service network path quality

[0163] Extract communication characteristics for each wireless data frame of all terminals received at the wireless LAN AP side. The communication characteristic information of each wireless data frame is used as the impact variable of the service executed by the terminal sending the data frame on the dependence of the wireless network quality. Perform one-dimensional convolutional filtering on this impact variable to obtain the quantization value of the dependence of the terminal service on the wireless network quality after eliminating disturbances. For the convenience of calculation, normalize this quantization value to the range of 0 - 100. The larger the value, the higher the dependence of the service on the network quality. When the network quality deteriorates, it is more likely to affect the service experience.

[0164] Suppose that the live broadcast service is executed on Terminal A. This service has high requirements for uplink bandwidth, packet loss rate, latency, etc., that is, it has a high dependence on network quality and requires better network quality. Assume that the dependence of this service on network quality is 80.

[0165] Suppose that the WeChat voice service is executed on Terminal B. This service has general requirements for uplink bandwidth, packet loss rate, latency, etc., that is, it has a general dependence on network quality, and the network quality can meet the service. Assume that the dependence of this service on network quality is 60.

[0166] Suppose that the web browsing service is executed on Terminal C. This service has low requirements for uplink bandwidth, packet loss rate, latency, etc., and can meet the service even when the network quality is poor. Assume that the dependence of this service on network quality is 10.

[0167] By continuously iteratively analyzing the wireless data frames of each terminal's uplink, an updated estimation matrix of the terminal uplink service network quality dependence (denoted as SW) can be obtained, as shown in Equation 8. This matrix needs to be continuously iteratively updated to maintain tracking of the current state.

[0168]

[0169] 4) Calculate the MIMO path weights of the antenna groups

[0170] When the AS matrix and the SW matrix change, it is necessary to recalculate the MIMO path weights of each antenna group. Perform a multiplication operation on the AS matrix and the SW matrix to calculate the MIMO path weights of each antenna group at the AP side of the wireless local area network in the system composed of the AP side of the wireless local area network and all terminals, denoted as AW, as shown in Equation 9.

[0171]

[0172] 5) Decision-making and execution process of antenna selection:

[0173] During normal service communication time (the time period other than the path state collection period), when the AP side of the wireless local area network is in the listening state, it is necessary to select the optimal receiving antenna group. Find the antenna group corresponding to the maximum weight in the AW matrix of Equation 9. In this embodiment, the weight of the first antenna group in the AW matrix is 140, and the weight of the second antenna group is 70. The first antenna group should be selected as the receiving antenna to meet the wireless communication capabilities of all terminal services in the system to the greatest extent.

[0174] Furthermore, the present invention also provides a MIMO receiving path selection device for the AP side of a wireless local area network, including at least one processor and a memory. The at least one processor and the memory are connected through a data bus. The memory stores instructions that can be executed by the at least one processor. After being executed by the processor, the instructions are used to complete the MIMO receiving path selection method for the AP side of the wireless local area network.

[0175] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for selecting a MIMO receiving path at the AP end of a wireless local area network, characterized in that It includes the following steps: If there is a service - type wireless data frame to be sent currently, switch to the available transmit antenna group, use the available transmit antenna group to send data, and clear the send status; If there is no service - type wireless data frame to be sent currently, switch to the optimal receive antenna group, and the AP is in the listening state. If a service - type wireless data frame is detected being received, set the receive status to "1"; If the current receive status is "1", then clear the receive status and update the service weight of the corresponding terminal in the terminal uplink service network quality dependence prediction matrix; If the receive status is "0", or after updating the service weight of the corresponding terminal in the terminal uplink service network quality dependence prediction matrix, check the training status; If the current training status is "1", then traverse all MIMO paths formed by antenna groups and terminals, perform AP transmit MIMO path optimization, update the antenna group - terminal MIMO transmit path status matrix, and perform AP receive MIMO path weight calculation to obtain an updated antenna group receive MIMO path weight matrix; among them, performing AP receive MIMO path weight calculation to obtain an updated antenna group receive MIMO path weight matrix is specifically implemented as follows: use the data of the antenna group - terminal MIMO transmit path status matrix and the terminal uplink service network quality dependence prediction matrix to calculate the sum of probabilities of each MIMO path formed by each antenna group and all terminals that satisfy all services, that is, the weight; perform matrix multiplication using the antenna group - terminal MIMO transmit path status matrix and the terminal uplink service network quality prediction matrix to obtain a new antenna group receive MIMO path weight matrix. The antenna group receive MIMO path weight matrix is a one - dimensional matrix with m rows, and each row represents the weight of the antenna group receive MIMO path corresponding to the row number. The row number of the maximum value AWmax is the antenna group of the current optimal receive MIMO path, and this antenna group can satisfy the quality requirements of all terminals' services for the uplink network with the highest probability; Before judging whether there is a service - type wireless data frame to be sent currently, it also includes: judging whether the information processing and decision - making module is executed for the first time. If it is "yes", initialize the key data structures and states; The initialization of the key data structures and states includes: constructing and initializing the data elements in the antenna group - terminal MIMO transmit path status matrix, the terminal uplink service network quality dependence prediction matrix, and the antenna group receive MIMO path weight matrix, where: The antenna group - terminal MIMO transmit path status matrix is an m - row and n - column matrix composed of m antenna groups and n terminals, where m≥2, the number of m is the same as the number of MIMO antenna groups owned by the AP, the number of n is the same as the maximum number of terminals that the AP can access. The data of each row represents the MIMO path status of 1 antenna group and all terminals, and the data of each column represents the MIMO path status of 1 terminal and all antenna groups; The uplink service network quality dependence estimation matrix of the terminal is a one-dimensional matrix with n rows composed of n terminals, and is used to record the service weights of each terminal. The larger the value of the service weight, the higher the dependence of the service on the network quality; The antenna group receives the MIMO path weight matrix, which is a one-dimensional matrix with m rows composed of m antenna groups, where m≥2, and is used to store the received MIMO path weights of each antenna group. The larger the path weight value, the more terminals and service requirements that the antenna group can match in the system.

2. The MIMO receiving path selection method for the wireless LAN AP side according to claim 1, wherein If there is a downlink service type wireless data frame to be sent currently, switch to the available transmit antenna group, including: extracting the physical address of the target terminal from the service type wireless data frame, finding the column corresponding to the target terminal in the antenna group-terminal MIMO transmit path status matrix, and finding the first available element in this column of data. The antenna group corresponding to the row number of this element is the available MIMO transmit antenna group, and drive the antenna selection module to switch the corresponding antenna group to be connected to the radio frequency circuit module to achieve the switching of the antenna group.

3. The method for selecting a MIMO receiving path at the wireless local area network AP side according to claim 1, characterized in that If the current is the receiving state, clear the receiving state and update the service weight of the corresponding terminal in the uplink service network quality dependence estimation matrix of the terminal, specifically including: when the AP receives the uplink service type wireless data frame sent by the terminal, extract the communication characteristics of the uplink service type wireless data frame, estimate the dependence of the terminal service on the network quality, and update the service weight of the corresponding terminal in the uplink service network quality dependence estimation matrix of the terminal.

4. The MIMO receiving path selection method for the wireless local area network AP side according to claim 1, wherein If the current is the training state, traverse all MIMO paths composed of antenna groups and terminals, perform AP transmit MIMO path optimization, and update the antenna group-terminal MIMO transmit path status matrix, specifically including: using a traversal method, sending training frames to all MIMO paths composed of each antenna group and each associated terminal, obtaining the MIMO correlation status of each MIMO antenna group-terminal path from the response frame, and updating the corresponding data elements in the antenna group-terminal MIMO transmit path status matrix.

5. The method for selecting a MIMO receiving path at the wireless local area network AP side according to claim 1, wherein Perform AP receive MIMO path weight calculation to obtain the updated antenna group receive MIMO path weight matrix, specifically including: through the current AP transmit MIMO path situation and the estimation of the dependence of the terminal uplink service on the network quality, calculate the probability weight that the MIMO receive path formed by each antenna group at the AP end meets the network quality requirements of all current terminal uplink services, and update the data elements of the antenna group receive MIMO path weight matrix.

6. The method for selecting a MIMO receiving path at the wireless local area network AP side according to claim 1, characterized in that The initialization of the key data structure and status is specifically implemented as follows: Initialize the antenna group-terminal MIMO transmit path status matrix, with all elements in the first row being 1 and all other rows being 0, that is, by default, all MIMO paths formed by the first antenna group and all n terminals are available transmit paths, where 1 represents an available transmit path and 0 represents an unavailable path; Initialize the uplink service network quality dependence estimation matrix of the terminal, with all values assigned as 0, that is, the initial service weights of the terminals are all 0, and 0 is the minimum weight; Initialize the receiving MIMO path weight matrix of the antenna group, and set all of them to 0. 0 is the minimum weight, which means that there is no appropriate receiving MIMO path by default in the initial state.

7. The method for selecting a MIMO receiving path at the wireless local area network AP side according to claim 2, wherein After sending the downlink service wireless data frame, clear the sending state and switch to the optimal receiving antenna group, so that the AP listens to the air interface and receives the uplink service wireless data frame of the terminal with the system-optimal receiving antenna group. The specific implementation includes: Scan the receiving MIMO path weight matrix of the antenna group, find the row corresponding to the maximum weight from it. The antenna group corresponding to this row is the system-optimal receiving antenna group. Using the receiving MIMO path formed by this antenna group can meet the requirement of the maximum air interface transmission efficiency of the system; if all weights are 0, it indicates that there is no connected terminal or the terminal does not send data. At this time, an antenna group corresponding to any row in the receiving MIMO path weight matrix of the antenna group can be selected; send a control signal to the antenna group selection module to select and enable the antenna group represented by this row number.

8. The method for selecting a MIMO receiving path at the wireless LAN AP side according to claim 3, wherein If the current is the receiving state, clear the receiving state and update the service weight of the corresponding terminal in the uplink service network quality dependence prediction matrix of the terminal. The specific implementation includes: After the AP receives the service wireless data frame sent by the j-th terminal, calculate and update the dependence degree of the service of the j-th terminal on the MIMO path quality in the uplink service network quality dependence prediction matrix of the terminal, and calculate and iteratively update the weight data in the uplink service network quality dependence prediction matrix of the terminal after each receipt of the service wireless data frame. Parse the MAC layer characteristic information data of the service wireless data frame, and calculate the dependence degree of the current service wireless data frame on the wireless network transmission capacity according to the data characteristics, frame type, service type, and QoS information of the MAC layer, and convert it into the dependence degree of the service on the MIMO path quality. The larger the value, the higher the dependence of the service on the MIMO path quality. The dependence degrees of all service wireless data frames sent by the j-th terminal on the wireless network transmission capacity are regarded as a series of input excitation sequences f(X0, X1, X2,...) of the wireless network transmission quality requirements superimposed with noise and disturbances from the 0th moment to an infinitely long moment. X0 represents the value at the 0th moment, X1 represents the value at the 0 + 1 moment, and so on. Perform one-dimensional convolutional filtering on this input excitation sequence, and extract the dependence degree p(n) of the terminal service on the communication bandwidth from it. The larger p(n) is, the stronger the dependence of the service on the network MIMO path quality. Use the calculated dependence degree p(n) of the terminal service on the MIMO path to replace the data in the j-th row of the uplink service network quality dependence prediction matrix of the terminal.

9. The method for selecting a MIMO receiving path at the wireless local area network AP side according to claim 4, wherein If the current is the training state, traverse all MIMO paths formed by the antenna group and the terminal, perform AP transmission MIMO path optimization, and update the antenna group-terminal MIMO transmission path status matrix. The specific implementation includes: When the AP iterates regularly or a new terminal is associated with the AP, substitute the antenna group number i and the terminal number j to be scanned this time, and obtain the MIMO path status between the i-th antenna group and the j-th terminal. Switch the antenna group to the i-th group; Send a training frame to the j-th terminal through the MIMO path formed by the i-th antenna group and the j-th terminal, and receive the feedback response frame of the j-th terminal; Extract the CSI information of the current MIMO path and the current MIMO path correlation from the response frame. When the MIMO path correlation is greater than the threshold, it indicates that the performance of the MIMO path formed by the i-th antenna group and the j-th terminal is poor. At this time, set the element in the i-th row and j-th column of the antenna group-terminal MIMO transmission path state matrix to 0, otherwise set it to 1. One terminal may form available MIMO paths with multiple antenna groups; 1 represents an available transmission path, and 0 represents an unavailable path; Update the values of i and j to prepare for the next path state acquisition; Return (i, j) to complete the acquisition of the current path state.

10. A MIMO receiving path selection device for a wireless local area network AP side, characterized in that, It includes at least one processor and a memory, and the at least one processor and the memory are connected through a data bus. The memory stores instructions that can be executed by the at least one processor. After being executed by the processor, the instructions are used to complete the wireless LAN AP-side MIMO reception path selection method according to any one of claims 1-9.

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