CN117479177A

CN117479177A - Communication method, communication device, and computer-readable storage medium

Info

Publication number: CN117479177A
Application number: CN202211372126.2A
Authority: CN
Inventors: 申晓曼; 张帅帅; 陈维熙; 潘淳
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-07-27
Filing date: 2022-11-03
Publication date: 2024-01-30

Abstract

A communication method, a communication apparatus, and a computer-readable storage medium are disclosed to improve the area and system capacity in which spatial multiplexing takes effect. The method comprises the following steps: and when the shared AP selects cooperative transmission, scheduling a first beam width used by the shared STA, and sending a cooperative transmission notification to the shared AP by the shared AP. The cooperative transmission notification includes a cooperative transmission parameter, where the cooperative transmission parameter is obtained according to a shared STA and a first beam width, and the cooperative transmission notification is used to instruct a shared AP to select, according to the cooperative transmission parameter, the shared STA and a second beam width for cooperative transmission, where the second beam width is one of beam widths adjustable by the shared AP. The first beamwidth is one of at least two beamwidths adjustable to the shared AP.

Description

Communication method, communication device, and computer-readable storage medium

Cross Reference to Related Applications

The present application claims priority to chinese application 202210894215.7 filed on 7.27 of 2022, which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a communication method, a communication device, and a computer readable storage medium.

Background

Wireless local area networks (wireless local area network, WLANs) are one type of wireless network access technology. The basic component of a WLAN is the basic service set (basic service set, BSS). Typically, a BSS includes an Access Point (AP) and a plurality of Stations (STAs) within the coverage area of the AP that establish an association therewith. With the increase of the number of mobile terminals and the amount of data transmitted, the demands of users for large uplink bandwidth and low delay on the WLAN network are increasing. Meanwhile, the WLAN network has more high-density deployment scenes, such as a park office scene, an industrial optical detection scene and the like, and the problem of co-channel interference is aggravated and the spectrum efficiency is reduced due to the close deployment of the APs. In a high-density deployment scene, a spatial multiplexing technology for reducing interference and cooperatively and concurrently transmitting by a plurality of BSSs is a key for improving the system capacity.

Currently, the IEEE 802.11be working group is discussing multi-AP collaborative spatial multiplexing (coordinated spatial reuse, CSR) technology. In general, an AP that preempts a transmission opportunity (transmission opportunity, TXOP) and allows other APs to cooperatively transmit is referred to as a shared AP (sharing AP), an associated STA for cooperative transmission that is scheduled by the shared AP is referred to as a shared STA, an AP that participates in cooperative transmission is referred to as a shared AP, and an associated STA for cooperative transmission that is scheduled by the shared AP is referred to as a shared STA.

The shared AP and the shared AP are neighbor same-frequency APs, and an overlapping area exists between the coverage area of the shared AP and the coverage area of the shared AP. In order to reduce co-channel interference caused by the shared AP or the shared STA to the transmission link of the shared AP and the shared STA during cooperative transmission, the shared AP needs to select the shared STA from STAs located in an area outside the overlapping area, resulting in limited STAs participating in CRS.

Disclosure of Invention

A communication method, a communication apparatus, and a computer-readable storage medium are provided to improve an effective area of collaborative spatial multiplexing.

A first aspect provides a communication method. The method comprises the following steps: and when the shared AP selects cooperative transmission, scheduling a first beam width used by the shared STA, and sending a cooperative transmission notification to the shared AP by the shared AP. Wherein the first beam width is one of at least two beam widths adjustable by the shared AP. The cooperative transmission notification includes a cooperative transmission parameter obtained according to the shared STA and the first beam width, and the cooperative transmission notification is used for indicating the shared AP to select the shared STA and the second beam width for cooperative transmission according to the cooperative transmission parameter. The shared STA is an STA in the associated STAs of the shared AP, and the shared STA is an STA in the associated STAs of the shared AP. The second beamwidth is one of the beamwidths adjustable by the shared AP. The shared AP dynamically selects a beam width for cooperative transmission from its own adjustable beam widths, and the coverage area of the shared AP can be changed along with the beam width selected by the shared AP, so that more STAs in the associated STAs of the shared AP have a chance to participate in the CRS.

In one possible implementation, the cooperative transmission parameters include at least two of a first beamwidth, an identity of the shared STAs, and a first interference limit. The first interference limit indicates a maximum interference acceptable to a transmission link between the sharing AP and the sharing STA at the first beamwidth. Thus, the shared AP can select a shared STA and a second beamwidth that have less interference to the transmission link between the shared AP and the shared STA at the first beamwidth than the first interference limit based on the cooperative transmission parameters.

In one possible implementation, the cooperative transmission parameters include an identification of at least one candidate shared STA and/or a candidate second beamwidth. Each candidate shared STA and/or candidate second beamwidth is selected based on the first beamwidth, the shared STA, and the channel measurement information. Each candidate shared STA is an STA in the associated STA of the shared AP, each candidate second beam width is a beam width in all adjustable beam widths of the shared AP, each candidate shared STA and/or candidate second beam width meets the interference constraint condition, and the channel measurement information is measured by the shared AP and/or the shared AP under different beam widths. Based on channel measurement information obtained by measuring the shared AP/the shared AP under different beam widths, candidate shared STAs meeting the interference limiting condition can be screened out from associated STAs of the shared AP more accurately, and candidate second beam widths meeting the interference limiting condition are selected from adjustable beam widths of the shared AP. Thus, the shared AP can select a shared AP that meets the interference limitation condition among the candidate shared STAs, and select a second beam width that meets the interference limitation condition among the candidate second beam widths. Furthermore, during cooperative transmission, the interference between the concurrent transmission links is controllable, so that the transmission rate of the concurrent transmission links can be improved, and the system capacity is improved.

In one possible implementation, meeting the interference constraint includes the second link having a first interference to the first link that is less than a first interference constraint of the first link. The first link is a transmission link between the shared AP and the shared STA under the first beam width, and the second link is a transmission link between the shared AP and the candidate shared STA under the candidate second beam width. The first interference limit indicates a maximum interference acceptable to the first link. The first interference is derived from channel measurement information. Therefore, the interference of the second link to the first link during cooperative transmission can be reduced, and the success rate and the transmission rate of the data transmission of the first link are ensured.

In one possible implementation, the meeting the interference constraint further includes the second interference constraint of the second link being greater than the second interference of the first link to the second link. The second interference limit indicates a maximum interference acceptable for the second link. The second interference is derived from channel measurement information. Therefore, the interference of the first link to the second link during cooperative transmission can be reduced, and the success rate and the transmission rate of the data transmission of the second link are ensured.

In one possible implementation, the coverage area formed by the shared AP on the horizontal plane is different at different beamwidths. Accordingly, the size of the overlapping area with the coverage of the shared AP can be adjusted by changing the coverage of the beam by switching the beam width, and the effective area of spatial multiplexing of the shared AP can be adjusted.

In one possible implementation, the method further includes the shared AP receiving signals from the associated STA of the shared AP, and/or the shared AP under at least two beamwidths, respectively, to obtain the channel measurement information. The channel measurement information includes measurement values between the shared AP and its associated STA, the associated STA of the shared AP or the shared AP under different beam widths, and can reflect channel quality conditions between the shared AP and its associated STA under different beam widths and channel interference conditions between the shared AP or the associated STA of the shared AP. Therefore, based on the channel measurement information, the more suitable first beam width, the shared STA and the second beam width can be selected for cooperative transmission, and interference control during cooperative transmission is better realized.

In one possible implementation, the shared AP selecting the first beam width used by the shared STA in scheduling the cooperative transmission includes the shared AP selecting the first beam width according to the shared STA and channel measurement information, where the channel measurement information includes channel measurement values between the shared AP and each associated STA of the shared AP under at least two beam widths, respectively. The channel measurement values between the shared AP and the associated STA under different beam widths can reflect the channel quality condition between the shared AP and each associated STA under each beam width, so that a more proper beam width can be selected to schedule the shared STA according to the channel measurement information.

In one possible implementation, the channel measurement value includes a received signal strength indicator value, and the first beamwidth is a beamwidth corresponding to a maximum value of at least two received signal strength indicator values between the shared AP and the shared STA. Generally, the larger the signal strength indication value is, the stronger the signal strength is, and the beam width corresponding to the maximum value in the signal strength indication value is selected as the first beam width, so that the channel quality between the shared AP and the shared STA is better under the first beam width, and the higher the transmission rate can be, thereby improving the system capacity.

In one possible implementation, the channel measurement value includes a path loss value, and the first beamwidth is a beamwidth corresponding to a minimum value of at least two path loss values between the shared AP and the shared STA. Generally, the smaller the path loss value is, the stronger the signal strength is, and the beam width corresponding to the minimum value in the path loss values is selected as the first beam width, so that the channel quality between the shared AP and the shared STA is better under the first beam width, and the higher the transmission rate can be, thereby improving the system capacity.

A second aspect provides a communication method. The method comprises the following steps: the first AP receives uplink signals from an associated STA of the first AP, an associated STA of the second AP and signals of the second AP under at least two beam widths respectively to obtain first channel measurement information. The first channel measurement information includes measurement values between the first AP and its associated STA, the second AP's associated STA and the second AP under different beamwidths, and can comprehensively reflect channel quality conditions between the first AP and its associated STA and channel interference conditions between the first AP and the shared AP or its associated STA under different beamwidths.

In one possible implementation, the uplink signal includes an acknowledgement frame. The confirmation frame has the characteristics of stable power and the like, and the measurement is performed based on the confirmation frame, so that the channel measurement information can be more accurate.

In one possible implementation, the method further includes the first AP receiving second channel measurement information from the second AP. The second channel measurement information includes channel measurements between the second AP and the first AP and/or associated STAs of the first AP, respectively, at least two beamwidths. Channel measurement information can be interacted between the first AP and the second AP, so that the first AP can master interference information between the associated STA of the first AP and between the associated STA of the second AP and the second AP more comprehensively.

In one possible implementation manner, the method further includes the first AP receiving a cooperative transmission notification from the second AP, where the cooperative transmission notification carries a cooperative transmission parameter, where the cooperative transmission parameter is obtained according to a first STA and a first beam width, the first STA is an STA for cooperative transmission selected by the second AP from associated STAs of the second AP, and the first beam width is a first beam width selected by the second AP for cooperative transmission from at least two beam widths adjustable by the second AP. The first AP selects a first beam width for cooperative transmission from at least two adjustable beam widths of the first AP and selects a first STA for cooperative transmission from associated STAs of the first AP according to cooperative transmission parameters and channel measurement information, wherein the channel measurement information comprises first channel measurement information and second channel measurement information, and the second channel measurement information comprises channel measurement values between the second AP and the first AP and/or the associated STAs of the first AP under at least two beam widths respectively. The second AP dynamically selects a beam width for cooperative transmission from its own adjustable beam widths, and the coverage area of the second AP can be changed along with the beam width selected by the second AP, so that more STAs in the associated STAs of the first AP have a chance to participate in the CRS.

In one possible implementation, the cooperative transmission parameters include at least two of a first beamwidth, a first STA, and a first interference limit, the first interference limit indicating a maximum interference acceptable by a transmission link between the second AP and the first STA at the first beamwidth. Because the channel measurement information can comprehensively reflect the interference information between the first AP and the second AP and the associated STA of the first AP and the associated STA of the second AP under different beam widths, the first AP can accurately select the second beam width and the second STA for cooperative transmission based on the channel measurement information and the cooperative transmission parameters, so that the interference of a transmission link between the first AP and the STA under the second beam width to a transmission link between the second AP and the first STA under the first beam width is smaller than the first interference limit. The interference between concurrent transmission links in cooperative transmission is controllable, and the success rate and the transmission rate of data transmission are ensured.

In one possible implementation, the cooperative transmission parameters include an identification of at least one candidate shared STA and/or a candidate second beamwidth. Each candidate shared STA and/or candidate second beamwidth is selected based on the first beamwidth, the shared STA, and the channel measurement information. Each candidate shared STA is an STA in the associated STA of the shared AP, each candidate second beam width is a beam width in all adjustable beam widths of the shared AP, each candidate shared STA and/or candidate second beam width meets the interference constraint condition, and the channel measurement information is measured by the shared AP and/or the shared AP under different beam widths. Therefore, the first AP can select the second STA meeting the interference limiting condition from the candidate second STAs, and select the second beam width meeting the interference limiting condition from the candidate second beam widths, so that the interference between concurrent transmission links during cooperative transmission can be reduced.

In one possible implementation, the interference of the transmission link between the second AP and the first STA under the first beamwidth to the transmission link between the first AP and the second STA under the second beamwidth is smaller than a second interference limit of the transmission link between the first AP and the second STA under the second beamwidth, the second interference limit being obtained according to the channel measurement information. Therefore, the transmission link between the second AP and the first STA under the first beam width during cooperative transmission can be reduced, interference on the transmission link between the first AP and the STA under the second beam width can be reduced, and the success rate and the transmission rate of data transmission can be ensured.

In one possible implementation, the coverage area formed by the first AP on the horizontal plane is different at different beamwidths.

A third aspect provides a communication device. The device is applied to shared AP and comprises a processing module and a receiving and transmitting module. The processing module is configured to select a first beam width used by the scheduling shared STA in cooperative transmission, where the first beam width is one of at least two beam widths with adjustable antennas of the shared AP. And the transceiver module is used for sending a cooperative transmission notification to the shared AP, wherein the cooperative transmission notification comprises a cooperative transmission parameter, the cooperative transmission parameter is obtained according to the shared STA and a first beam width, the cooperative transmission notification is used for indicating the shared AP to select the shared STA and a second beam width for cooperative transmission according to the cooperative transmission parameter, and the second beam width is one beam width of the beam widths of which the antennas are adjustable.

In one possible implementation, the cooperative transmission parameters include at least two of a first beam width, an identification of the shared STA, and a first interference limit, such that the shared AP selects the shared STA and a second beam width according to the cooperative transmission parameters and channel measurement information, the first interference limit indicating a maximum interference acceptable to a transmission link between the shared AP and the shared STA at the first beam width, the channel measurement information being measured by the shared AP and/or the shared AP at different beam widths.

In one possible implementation, the cooperative transmission parameter includes an identification of a candidate shared STA and/or a candidate second beam width, where the candidate shared STA and/or the candidate second beam width are selected according to a first beam width, a shared STA, and channel measurement information, the candidate shared STA includes at least one STA among associated STAs of the shared AP, the candidate second beam width includes at least one beam width among all adjustable beam widths of the shared AP, the candidate shared STA and/or the candidate second beam width meets an interference constraint, and the channel measurement information is measured by the shared AP and/or the shared AP under different beam widths.

In one possible implementation, meeting the interference constraint includes the second link having a first interference to the first link that is less than a first interference constraint of the first link. The first link is a transmission link between the shared AP and the shared STA under a first beam width, the second link is a transmission link between the shared AP and the candidate shared STA under a candidate second beam width, and the first interference is obtained according to channel measurement information.

In one possible implementation, the meeting the interference constraint further includes the second interference constraint of the second link being greater than the second interference of the first link to the second link. Wherein the second interference is derived from channel measurement information.

In one possible implementation, the coverage of the antenna on the horizontal plane is different at different beamwidths.

In one possible implementation, the transceiver module is configured to receive signals from the associated STA of the shared AP, and/or the signal of the shared AP under at least two beamwidths, respectively, to obtain the channel measurement information.

A fourth aspect provides a communication device. The device is applied to a first AP and comprises a transceiver module. And the receiving and transmitting module is used for respectively receiving the uplink signals of the associated STA of the first AP, the associated STA of the second AP and the signal of the second AP under at least two beam widths so as to obtain the first channel measurement information.

In one possible implementation, the uplink signal includes an acknowledgement frame.

In one possible implementation, the transceiver module is configured to receive second channel measurement information from a second AP. Wherein the second channel measurement information includes channel measurement values between the second AP and the first AP and/or associated STAs of the first AP under at least two beamwidths, respectively.

In one possible implementation, the apparatus further includes a processing module. And the transceiver module is used for receiving the cooperative transmission notification from the second AP. The cooperative transmission notification carries a cooperative transmission parameter, wherein the cooperative transmission parameter is obtained according to a first STA and a first beam width, the first STA is the STA for cooperative transmission selected by a second AP from associated STAs of the second AP, and the first beam width is the first beam width for cooperative transmission selected by the second AP from at least two adjustable beam widths of the second AP. And the processing module is used for selecting a second beam width for cooperative transmission from at least two beam widths which are adjustable by the first AP according to the cooperative transmission parameters and the channel measurement information, and selecting a second STA for cooperative transmission from the associated STAs. The channel measurement information includes first channel measurement information and second channel measurement information, and the second channel measurement information includes channel measurement values between the second AP and the first AP and/or associated STAs of the first AP under at least two beamwidths, respectively.

In one possible implementation, the cooperative transmission parameters include at least two of a first beamwidth, an identification of the first STA, and a first interference limit indicating a maximum interference acceptable for a transmission link between the second AP and the first STA at the first beamwidth.

In one possible implementation, the cooperative transmission parameters include an identification of at least one candidate shared STA and/or a candidate second beamwidth. Each candidate shared STA and/or candidate second beamwidth is selected based on the first beamwidth, the shared STA, and the channel measurement information. Each candidate shared STA is an STA in the associated STA of the shared AP, each candidate second beam width is a beam width in all adjustable beam widths of the shared AP, each candidate shared STA and/or candidate second beam width meets the interference constraint condition, and the channel measurement information is measured by the shared AP and/or the shared AP under different beam widths.

In one possible implementation, the interference of the transmission link between the second AP and the first STA under the first beamwidth to the transmission link between the first AP and the second STA under the second beamwidth is less than a second interference limit of the transmission link between the first AP and the second STA under the second beamwidth. Wherein the second interference limit is derived from the channel measurement information.

A fifth aspect provides a communication device. The apparatus comprises a processor for communicating with other communication apparatuses and a communication interface for executing a set of instructions to implement the channel measurement method of the first aspect or any possible implementation of the second aspect.

A sixth aspect provides a computer-readable storage medium. The computer readable storage medium comprises instructions which, when run on a computer, cause the computer to implement the communication method of the first aspect or any possible implementation of the first aspect, or of the second aspect or any possible implementation of the second aspect.

Drawings

Fig. 1 is a schematic structural diagram of a WLAN system provided in the present application;

fig. 2 is a schematic structural diagram of an AP with adjustable beam width provided in the present application;

fig. 3 is a schematic structural diagram of another WLAN system provided in the present application;

fig. 4a is a schematic diagram of one possible deployment scenario of an AP provided herein;

Fig. 4b is a schematic diagram of another possible deployment scenario of an AP provided herein;

fig. 5 is a schematic flow chart of cooperative transmission between APs provided in the present application;

fig. 6 is a schematic flow chart of a channel measurement method provided in the present application;

fig. 7 is a schematic flow chart of another channel measurement method provided in the present application;

FIG. 8 is a flow chart of a communication method provided in the present application;

fig. 9a is a schematic diagram of a scenario of one transmission direction of two transmission links in cooperative transmission provided in the present application;

fig. 9b is a schematic view of another transmission direction of two transmission links in cooperative transmission provided in the present application;

fig. 9c is a schematic view of another transmission direction of two transmission links in cooperative transmission provided in the present application;

fig. 10 is a schematic structural diagram of a communication device provided in the present application;

fig. 11 is a schematic structural diagram of another communication device provided in the present application.

Detailed Description

With the development of the mobile internet and the popularization of intelligent terminals, data traffic is rapidly increasing. Wireless local area networks (wireless local area network, WLAN) are one of the mainstream mobile broadband access technologies by virtue of high rate and low cost. With the increasing number of user devices and the increasing demand for internet of things (Internet of things, ioT), a high-density deployment scenario (high-dense deployment scenarios) is one of the core scenarios of wireless networks. High dense deployment refers to deploying a large number of wireless Access Points (APs) and a large number of Active Stations (STAs) within a limited geographic coverage area. High density deployments have led to dramatic increases in the demand for transmission resources.

The communication method of the wireless local area network provided by the application can be applied to a fourth generation (4G) communication system, such as long term evolution (long term evolution, LTE), a fifth generation (5th generation,5G) communication system, such as a 5G New Radio (NR), or various future communication systems.

The communication method provided by the application can be applied to a WLAN system and can be applied to an IEEE 802.11 system standard, such as an IEEE 802.11be standard draft, or a standard of the next generation or more.

Embodiments provided herein will be described in detail below with reference to the accompanying drawings.

One type of WLAN system 100 to which the present embodiment may be applied may include a plurality of Stations (STAs) including an AP and a non-AP STA. Alternatively, the WLAN system 100 may include: one or more APs, one or more non-AP STAs. In the embodiment of the present application, the non-AP STA may be abbreviated as STA. Wherein an AP may be associated with one or more STAs, the AP may schedule transmission resources for the STAs associated with the AP and communicate with the scheduled STAs on the scheduled transmission resources. The AP may connect to a distribution system (distributed system, DS). It is understood that reference herein to "a plurality of" may refer to two and more than two, or greater than or equal to two. It is also understood that reference herein to "multiple APs" is an abbreviation for "multiple APs" and "multiple STAs" is an abbreviation for "multiple STAs".

As shown in fig. 1, a WLAN system 100 may include a plurality of APs and a plurality of STAs. Fig. 1 illustrates two APs, with each AP connecting two STAs. It will be appreciated that more APs and more STAs may also be included in the WLAN system. In fig. 1, two APs are denoted by AP101-1 and AP101-2, respectively, and two STAs connected to AP101-1 are denoted by STA102-1 and STA 102-2. Two STAs connected by AP101-2 are denoted by STA102-3 and STA 102-4. The AP101-1 may associate the STA102-1 with the STA102-2, may provide services for the STA102-1 and the STA102-2, and the AP101-1 is a serving AP for the STA102-1 and the STA 102-2. AP101-2 associates STA102-3 with STA102-4, may serve STA102-3 and STA102-4, and AP101-2 is the serving AP for STA102-3 and STA 102-4.

In order to better understand the solution provided in the present application, the following describes related concepts in the WLAN system according to the embodiment of the present application.

An AP, an entity with STA functionality, may provide access to distribution services for associated STAs through a Wireless Medium (WM). The AP may include STAs and distributed system access functions (distribution system access function, DSAF). An AP may also be referred to as a wireless access point or bridge or hotspot. The AP may access a server or a communication network. The AP may serve as a hub for the WLAN system. The AP may be a base station, router, gateway, repeater, communication server, switch, bridge, or the like. Here, for convenience of description, the above-mentioned devices are collectively referred to as an AP in the embodiments of the present application.

STA, referred to herein as a non-AP station, a logical entity, is a single addressable instance of the medium access control (medium access control, MAC) layer and physical layer (PHY) interfaces to the wireless medium. The STA may be various user terminals, user equipment, access apparatuses, subscriber stations, subscriber units, mobile stations, user agents, user equipment, or other names with wireless communication capabilities, where the user terminals may include various handheld, in-vehicle, wearable, computing, or other processing devices connected to a wireless modem, as well as various forms of User Equipment (UE), mobile Stations (MSs), terminals (terminals), terminal devices (terminal equipment), portable communication devices, handsets, portable computing devices, entertainment devices, gaming devices or systems, global positioning system devices, or any other suitable devices configured to communicate over a network via a wireless medium, and so forth. Here, for convenience of description, the above-mentioned apparatuses are collectively referred to as STAs in the embodiments of the present application.

Transmission opportunities (transmission opportunity, TXOPs) are the basic unit of wireless channel access. The TXOP consists of an initial time and a maximum duration (TXOP limit). A station that obtains a TXOP may not re-contend for the channel during the TXOP limit time and continuously use the channel to transmit multiple data frames. The TXOP may be obtained via two ways of contention or hybrid coordinator (hybrid coordinator, HC) allocation. Among other things, the TXOP obtained via contention may be referred to as an enhanced distributed channel access (enhanced distributed channel access, EDCA) TXOP. The TXOP obtained via HC allocation may be referred to as a hybrid coordination function control channel access (hybrid coordination function controlled channel access, HCCA) TXOP. It should be understood that the present application does not relate to the acquisition of TXOPs, and specific details of the manner in which TXOPs are acquired may be found in the prior art.

In a WLAN system, each AP and STAs associated with the AP may form a basic service set (basic service set, BSS). For example, in FIG. 1, AP101-1, STA102-1, and STA102-2 may form a BSS103, and AP101-2, STA102-3, and STA102-4 may form a BSS104. The APs not belonging to the same BSS are non-associated APs, and the STAs not belonging to the same BSS are non-associated STAs. For example, in FIG. 1, AP101-1 is a non-associated AP for STA102-3 and STA102-4, and STA102-3 and STA102-4 are non-associated STAs for AP 101-1. The relationship between STA102-1, STA102-2 and AP101-2 is the same. The same transmission resource can be used by a plurality of BSSs, so that the utilization rate of the transmission resource of the wireless local area network can be improved. APs in different BSSs may cooperatively use the same transmission resources to achieve cooperative transmission.

As the range and number of STAs in use increases, the APs deployed in WLANs become denser in order for wireless networks to cover the STAs entirely. Therefore, coverage areas of multiple co-frequency BSSs (BSSs to which multiple co-frequency APs belong are co-frequency BSSs) may overlap, so as to form an overlapping basic service set (overlap basic service set, OBSS for short), that is, multiple overlapping-coverage APs transmit downlink signals to STAs associated with each AP on the same channel, or multiple STAs transmit uplink signals to APs associated with each STA on the same channel. For example, in fig. 1, where AP101-1 and AP101-2 are co-frequency APs, BSSs where two coverage areas, BSS103 and BSS104, overlap is an OBSS. It should be understood that fig. 1 is only exemplary, and should not limit the network architecture of the wireless local area network to which the present application is applicable, for example, the network architecture may further include more BSSs, each BSS may further include more STAs, or a portion of the BSSs may not further include an AP. The overlapping area of multiple BSSs may further include more STAs, etc., and embodiments of the present application are not limited herein.

Cooperative transmission refers to two or more APs in a WLAN system that serve different STAs on the same transmission resources, including Uplink (UL) transmission and/or Downlink (DL) transmission. One way of multi-AP cooperative transmission is cooperative spatial multiplexing (coordinated spatial reuse, CSR). The method and the device can be suitable for the cooperative transmission mode of the CSR.

When multiple APs cooperatively transmit, the AP that preempts the TXOP is generally referred to as shared AP (sharing AP). An AP that transmits in conjunction with the shared AP is referred to as a shared AP (shared AP). The shared AP and the shared AP are the same frequency APs. Of course, the shared AP may also be referred to as a master AP or other name, and the shared AP may also be referred to as a slave AP or other name. At the next TXOP, the shared AP may also be the same AP, or may change. Among STAs associated with the shared AP, STAs participating in cooperative transmission may be referred to as shared STAs, and STAs associated with the shared AP, STAs participating in cooperative transmission may be referred to as shared STAs.

In this embodiment, a shared AP and one or more shared APs cooperatively transmit on a channel. For example, the bandwidth of the co-transmitted channel may be 20MHz, 40MHz, 80MHz, 160MHz, 240MHz, 320MHz, or other bandwidths supported by the WLAN. Assuming that the bandwidth of the co-transmitted channel is 80MHz, the shared AP and one or more shared APs transmit cooperatively on the 80MHz channel, both the shared AP and the shared APs may use the 80MHz channel.

The AP may allocate resources to the associated STAs using an orthogonal frequency division multiple access (orthogonal frequency division multiple access, OFDMA) technique that further divides the air-interface wireless channel time-frequency resources into a plurality of orthogonal resources, which are referred to as Resource Units (RUs). The AP may allocate resources based on orthogonal resources when allocating resources to STAs. For example, the AP may allocate based on RU, or may allocate based on a group of RU. The AP allocates different orthogonal resources to different STAs at the same time, so that multiple STAs can efficiently access the channel.

When multiple APs cooperatively transmit, a shared AP may assign a channel to one STA associated with the shared AP, or to multiple STAs associated with the shared AP based on OFDMA techniques, or a shared AP may assign a channel to one STA associated with the shared AP, or to multiple STAs associated with the shared AP based on OFDMA techniques.

The shared AP and the shared AP cooperatively transmit on the channel, which means that the shared AP and the shared AP can use the entire channel, and how the shared AP and the shared AP allocate RU of the channel to the STA specifically, the embodiment of the present application is not limited. The shared AP and the shared AP may allocate part or all of the resources of the channel to the sharing STA and the shared STA being scheduled.

Taking two APs for example, in the WLAN system shown in fig. 1, the AP101-1 and the AP101-2 may use the same transmission resource for cooperative transmission. The transmission resources may be channel-granularity or RU-granularity. For example, with the granularity of the channel, the AP101-1 and the AP101-2 use the same channel for cooperative transmission. Assuming that the bandwidth of the channel for cooperative transmission is 80MHz, both AP101-1 and AP101-2 can use the channel with the 80MHz bandwidth. The AP101-1 may allocate the 80MHz bandwidth channel to either STA102-1 or STA102-2 in its entirety (single STA schedule), or to STA102-1 in part, to STA102-2 in part (multi STA schedule). The AP101-2 may also allocate the 80MHz bandwidth channel to either STA102-3 or STA102-4 in its entirety, or to STA102-3 in part, or to STA102-4 in part. On the co-transmitted channel, AP101-1 may communicate with STA102-1/STA102-2 and AP101-2 may communicate with STA102-3/STA 102-4.

In cooperative transmission, the transmission link between the shared AP and the shared STA and the transmission link between the shared AP and the shared STA use the same or partially the same time-frequency resource (simply can be understood as using the same channel in the same period), and co-channel interference exists between the two concurrent transmission links. When there is overlap between the coverage of the shared AP and the coverage of the shared AP, that is, when the BSS to which the shared AP belongs and the BSS to which the shared AP belongs are OBSS, STAs located in the overlapping area may introduce serious co-channel interference if they participate in cooperative transmission. Therefore, in order to reduce interference, the shared AP does not select STAs located in the overlapping region when selecting STAs participating in cooperative transmission among its associated STAs. When the overlapping area of the shared AP and the shared AP is larger and more STAs of STAs associated with the shared AP are located in the overlapping area, the STAs capable of participating in cooperative transmission in the STAs associated with the shared AP are limited.

In addition, in order to reduce interference between concurrent transmission links, the current scheme negotiates transmission power between the shared AP and the shared AP, and it is generally required that the shared AP (downlink scheduling) or the shared STA (uplink scheduling) reduce the transmission power, which may cause degradation of signal strength and affect the transmission rate between the shared AP and the shared STA. And, if the transmission direction between the shared AP and the shared STA is uplink, the shared AP needs to control the transmission power of the shared STA. However, in practice, the effect of regulating the transmit power of the STA is not ideal. For example, some STAs do not support or respond to indications of the AP to adjust transmit power that it sends. For example, even if the STA can respond to the indication of adjusting the transmission power sent by the AP, due to the difference of the specifications of the radio frequency modules, there may be a situation that the adjustment of the transmission power is inaccurate, so that the interference between the concurrent transmission links is uncontrollable, which also affects the cooperative transmission rate and reduces the system capacity.

Therefore, the present application provides the following embodiments to improve the effective area of CRS and the throughput rate of cooperative transmission, so that more STAs of STAs associated with a shared AP have a chance to participate in cooperative transmission.

The WLAN system of this embodiment includes at least one AP with adjustable beam width. An AP with adjustable beam width refers to an AP that has multiple beam widths and can switch the operating beam width to a specified beam width of the multiple beam widths. The size and number of beamwidths for the APs in the WLAN system may be the same or different. As shown in fig. 2, fig. 2 is a schematic structural diagram of another WLAN system provided in the present application. In fig. 2, the WLAN system includes two APs, which are both APs with adjustable beam width, and each AP is exemplified by associating two STAs. It will be appreciated that more APs and more STAs may be included in the WLAN system, and that some or all of the APs in the WLAN system may be beam-width adjustable APs, which is not limited herein. In fig. 2, two APs are denoted by AP1 and AP2, respectively. The STAs associated with AP1 are denoted by STA1-1 and STA 1-2. The STAs associated with AP2 are denoted STA2-1 and STA 2-2. AP1, STA1-1 and STA1-2 belong to BSS1, AP2, STA2-1 and STA2-2 belong to BSS2.

Multiple APs in the WLAN system may be connected to a controller (access controller, AC) through a switch, and information may be exchanged between the APs through the switch and the controller. The networking manner in fig. 2 is merely an example, and a plurality of APs may be connected to a controller through the same switch, or the controller and the switch may be integrated into one network device, which is not limited herein.

The embodiment in this scheme is implemented based on an AP with adjustable beam width, and for brevity of description, the AP with adjustable beam width is sometimes referred to as AP hereinafter. When the WLAN system further includes a non-beam width adjustable AP, related operations of the non-beam width adjustable AP in the scenarios of channel measurement and cooperative transmission may refer to related prior art, which is not described in the present application.

Fig. 3 is a schematic structural diagram of an AP with adjustable beam width provided in the present application. Specifically, the beam width adjustable AP includes an antenna, a processor, and a beam width adjustment device. Wherein the antenna has at least two beamwidths that are adjustable. The number of antennas with adjustable beamwidths may be 2, 3, 4, 6, 10 or more. Each beam width is greater than 0 degrees and less than or equal to 180 degrees. The processor is used for selecting one beam width from all adjustable beam widths of the antenna to receive uplink signals or transmit downlink signals. The antenna comprises at least two antenna elements. The beam width adjusting device is used for adjusting the amplitude and the phase of the radio frequency signals fed into each unit antenna so that the antennas transmit and receive signals under the beam width specified by the processor. The beam width adjusting device is, for example, a phase adjuster, a phase shifter, a gain adjuster, a precoder, or the like.

In the antenna pattern, the radiation intensity decreases by 3 decibels (dB) on both sides of the maximum radiation direction, i.e. the angle between two points at which the power density decreases by half is defined as the beam width, also called 3dB beam width, or half power beam width (half power beam width, HPBW). The larger the beam width of the antenna, the larger the coverage of the beam, the larger the antenna gain at the coverage edge position, the larger the signal strength, the larger the interference to the AP and STA of the OBSS at the same transmit power, and the larger the interference received from the AP and STA of the OBSS. The smaller the beam width of the antenna, the smaller the coverage of the beam, the more the radiated energy of the beam is concentrated in the maximum radiation direction according to the principle of conservation of energy radiated by the antenna, the smaller the antenna gain at the edge of the coverage, the smaller the signal strength, the less interference to the AP and STA of the OBSS at the same transmission power, and the less interference received from the AP and STA of the OBSS.

In an actual application scenario, an AP is generally installed in a place in a high hanging manner, for example, a ceiling, a wall hanging, a column holding, or the like, and the radiation direction of an antenna of the AP points to the ground, so that the AP can provide services for STAs in the place. In combination with the deployment scenario of the AP, the beam width may also be interpreted as a pitch angle corresponding to a coverage area formed by 3dB of the decrease of the radiation intensity of the antenna (hereinafter referred to as a 3dB coverage area for short), where the pitch angle is an included angle formed by two endpoints of the maximum diameter of the 3dB coverage area and connecting lines of the AP, respectively. As shown in fig. 4a and 4b, the AP in fig. 4a is deployed in a ceiling-mounted manner, and the AP in fig. 4b is deployed in a wall-mounted manner, wherein the dashed lines in the figures indicate coverage areas of the AP on a horizontal plane under different beam widths, and the coverage areas corresponding to the different beam widths are different in size. The number and size of beam widths in fig. 4a and 4b are merely illustrative, and the number and size of beam widths is determined according to the actual situation of the antenna of the AP, and are not limited herein. Taking the coverage of 3dB as an example in fig. 4a, pitch angles (beam widths) corresponding to coverage 1 to coverage 4 are sequentially from α1 to α4, pitch angle sizes are ordered as α1 < α2 < α3 < α4,3dB coverage sizes are ordered as coverage 1 < coverage 2 < coverage 3 < coverage 4, and antenna gain sizes at 3dB coverage edge positions are ordered as coverage 4 < coverage 3 < coverage 2 < coverage 1.

The smaller the beam width is, the better the quality of the transmission link between the AP and the STA may be, among the plurality of beam widths of the AP, under the premise of ensuring coverage to the STA. For example, in fig. 4a, the AP covers STA1 with the beam widths α1 to α4, and since the antenna gain of the AP with the beam width α1 is the largest, the signal strength is the strongest, and the beam width α1 may be the optimal beam width when STA1 is scheduled. The AP does not cover STA2 under the beam width α1, covers STA2 under all of α2 to α4, and the beam width α2 may be the optimal beam width when STA2 is scheduled. Similarly, when STA3 is scheduled, the beam width α3 may be the optimal beam width. When STA4 is scheduled, it is necessary to ensure that the coverage of the AP can cover STA4, and the beam width α4 may be the optimal beam width.

In this embodiment, the maximum radiation directions of the antennas at different beamwidths are the same or substantially the same. That is, when the AP switches between different beamwidths, the beamwidth changes while the beamdirection does not change. And, the maximum radiation direction of the beam may be perpendicular to the horizontal plane, or may have a certain inclination angle with the horizontal plane, which depends on the position and pose of the AP during actual deployment, and is not limited herein. In this embodiment, the meaning of an AP or an AP of an antenna under a certain beam width is the same as the meaning of an AP using the beam width for data transmission.

When the AP performs uplink or downlink scheduling on its associated STA, an appropriate beam width may be selected for the scheduled STA to perform scheduling, so as to increase the antenna gain as much as possible and reduce interference to the OBSS in the WLAN system. Illustratively, as shown in fig. 2, coverage a in fig. 2 represents coverage of an antenna of AP1 with a beam width β1, and coverage B represents coverage of an antenna of AP1 with a beam width β2. The STA1-1 is closer to the AP1 and is positioned in the coverage A and the coverage B; STA1-2 is farther from AP1, within coverage B but outside coverage a. When AP1 schedules STA1-1, beam width β1 may be employed to increase antenna gain while also reducing interference to AP2, STA2-1 and STA 2-2. When AP1 schedules STA1-2, then beam width β2 may be employed to ensure that the coverage of AP1 can be covered by STA1-2. The same applies to the scheduling of its associated STA by AP2, which selects an appropriate beamwidth for the scheduled STA to schedule.

In the cooperative transmission scenario, if the shared AP is an AP with adjustable beam width, the beam width used when the shared STA is scheduled is flexibly selected, so that more STAs in the BSS to which the shared AP belongs can have a chance to participate in cooperative transmission. For example, in fig. 2, AP1 is a shared AP, and AP2 is a shared AP. Coverage C represents the coverage of the antenna of AP2 at beam width β3, with both STA2-1 and STA2-2 being located within coverage C, but STA2-1 also being located within coverage B of AP 1. In cooperative transmission, if the STA scheduled by the AP1 is STA1-1, the AP1 may use the beam width β1 to perform data transmission with STA 1-1. At this time, the beam width of the AP1 corresponds to the coverage area a, the overlapping coverage area of the AP1 and the AP2 becomes smaller, the STA2-1 is located outside the coverage area a of the AP1, and the interference between the STA2-1 and the AP1 becomes smaller. Then, when the AP2 selects a shared STA that participates in cooperative transmission among its associated STAs, the STA2-1 has an opportunity to be selected to participate in cooperative transmission.

The implementation method of cooperative transmission is described in detail below when the AP with adjustable beam width participates in cooperative transmission. The cooperative transmission can be divided into three phases, namely a preparation phase, a declaration phase, and a data transmission phase. As shown in fig. 5, in the preparation phase, each AP in the WLAN system measures channel measurement information with the STA and other APs. In the declaration phase, the shared AP preempted to the TXOP in the WLAN system determines a shared STA participating in cooperative transmission, determines a first beam width used when scheduling the shared STA according to channel measurement information, and sends a cooperative transmission notification to the shared AP according to the determined STA and the beam width to instruct the shared AP to select the shared STA participating in cooperative transmission and the first beam width used when scheduling the shared STA. In the data transmission phase, the shared AP transmits data in parallel with the transmission link between the shared STA and the shared AP in the first beam width, and the shared AP transmits data in parallel with the transmission link between the shared STA and the shared AP in the second beam width.

Specifically, in the preparation stage, the AP performs channel measurement with multiple STAs and the same-frequency AP under different beam widths, respectively, to obtain channel measurement information. The channel measurement information includes, for example, channel measurement values between the AP and each STA in the BSS to which the AP belongs under different beam widths, and channel measurement values between the AP and each STA in the OBSS. The channel measurement may be a received signal strength indication (receive signal strength indicator, RSSI), a Path Loss (PL) value, or a signal to interference and noise ratio (signal to interference noise ratio, SINR) value, etc.

In order to improve the channel detection efficiency and reduce the channel detection overhead, a plurality of APs in the WLAN system may cooperatively measure, that is, after the plurality of APs negotiate, send downlink signals for measurement synchronously, or receive uplink signals, so as to measure a channel and obtain channel measurement data. And after obtaining the respective channel measurement information, the APs interact with each other, so that the APs can grasp the channel measurement information in the BSS to which the AP belongs and the channel measurement information between the BSS to which the AP belongs and the OBSS. The channel measurement information between a BSS and its OBSS is interference measurement information, and may include channel measurement values (interference measurement values) between the AP in the BSS and the AP in the OBSS and each STA under different beam widths, respectively, and interference measurement values between the AP in the OBSS and the AP in the BSS and each STA under different beam widths, respectively.

There are various methods for the AP to obtain channel measurement information between the AP and the STA, and this embodiment provides two measurement methods, and the AP and the STA may also implement channel measurement in other manners. In the first measurement method, the AP measures channel measurement information. Specifically, the AP may receive Uplink (UL) signals from the associated STA and the non-associated STA (STA within the OBSS) respectively at different beamwidths to obtain channel measurements between the AP and each STA. And in the second measurement method, the STA measures channel measurement information. Specifically, the AP transmits Downlink (DL) signals respectively under different beamwidths, and the associated STA and the non-associated STA receive the downlink signals to obtain channel measurement values and report the respective channel measurement values to the respective associated AP, so that the AP can obtain the channel measurement values between the AP and each STA. The two measuring methods are described in detail below with reference to the accompanying drawings. In this embodiment, the uplink signal and the uplink frame are often used alternately, and the downlink signal and the downlink frame are often used alternately.

Fig. 6 is a schematic flow chart of a channel measurement method provided in the present application, as shown in fig. 6. Fig. 6 illustrates channel measurements between an AP and associated STAs and non-associated STAs based on uplink frame measurements at different antenna beamwidths. In fig. 5, taking cooperative measurement of AP1 and AP2 as an example, it is assumed that antennas of AP1 and AP2 support 4 beamwidths of 60 degrees, 90 degrees, 120 degrees and 150 degrees, and of course, more APs may participate in cooperative measurement, and AP1 and AP2 may support beamwidths of other different sizes and numbers. During the measurement phase, there is no master-slave division between APs of the WLAN system.

Uplink frames such as management frames, control frames, data frames, etc., transmitted by the STA can be used by the AP for channel measurements to obtain channel measurements. The uplink frame sent by the STA may be actively sent by the STA or may be triggered and sent by the AP. The following description will take an example in which an AP triggers an STA to transmit an uplink frame to measure a channel.

AP1 periodically transmits an indication frame to AP2 to inform AP2 that it is ready to receive uplink frames from STA1-1 and STA1-2 associated with AP 1. The instruction frame may be a Trigger Frame (TF) or a management frame such as a beacon (beacon) frame. Alternatively, the indication frame may carry a time interval for switching the beam width, so that the AP1 and the AP2 can switch the beam width synchronously. After a Short inter-frame space (SIFS), AP1 sequentially switches the antenna beam width and sends downlink frames to associated STA1-1 and STA 1-2. The downlink frame may be a data frame to trigger the STA to reply to the acknowledgement frame. The acknowledgement frame may be a block acknowledgement (block Acknowledgement, BA) frame or an ACK frame. Wherein, the BA frame transmission power is stable, the modulation order (modulationand coding scheme, MCS) and the control flow are not changed greatly, and the measurement data obtained based on the BA frame measurement is more stable and accurate. To reduce overhead, the downlink frame may be a null frame or a short data frame. Of course, the downlink frame may be a beacon frame or the like. STA1 and STA1-2 reply to the uplink frame for the downlink frame. After the AP1 receives the uplink frames from the STA1-1 and the STA1-2 in the corresponding beam width, the RSSI value is read as a channel measurement value between the AP1 and the corresponding STA in the current beam width. Meanwhile, the AP2 sequentially switches the antenna beam width, receives uplink frames from the STA1-1 and the STA1-2, and reads the RSSI value as a channel measurement value between the AP2 and the corresponding STA under the current beam width. The time intervals of the switching beam widths of the AP1 and the AP2 are consistent, so that the AP1 and the AP2 can finish the measurement of the same number of beam widths in a measurement period, and the measurement efficiency is improved. The measurement of AP2 is similar to that of AP1, and thus will not be described in detail here. The AP2 may send the downlink frame simultaneously with the AP1, or after the AP1 sends the downlink frame, the AP1 and the AP2 temporarily switch the beam width, the AP2 sends the downlink frame to the associated STA, and after the AP1 and the AP2 receive the uplink frame of the associated STA of the AP2, the AP1 and the AP2 sequentially switch the beam width, so as to complete the measurement of other beam widths. Of course, AP1 and AP2 may also perform measurements of all beam widths respectively in different time periods, which is not limited herein.

For example, AP1 and AP2 switch the beam width to 60, and AP1 transmits downlink frame 1 to STA1-1 and STA 1-2. STA1-1 and STA1-2 reply to uplink frame 1 for downlink frame 1.AP1 and AP2 respectively receive uplink frame 1 at 60 deg. beam width, and AP1 can obtain the space between AP1 and STA1-1 at 60 deg. beam widthAnd STA 1-2->AP3 can give AP2 a beam width of 60℃and STA1-1 +.>And STA 1-2->Then, the AP1 and the AP2 switch the beam width to 90 °, and the AP1 transmits the downlink frame 2 to the STA1-1 and the STA 1-2. STA1-1 and STA1-2 reply to uplink frame 2 for downlink frame 2.AP1 and AP2 respectively receive uplink frame 2 under 90 deg. beam width, AP1 can obtain +.>And STA 1-2->AP2 may obtain a beam width of 90℃between AP2 and STA1-1And STA 1-2->And so on until AP1 has completed all beamwidth measurements. Thus, AP1 obtains channel measurement information between AP1 and STAs within BSS1, and AP2 obtains channel measurement information between STAs with BSS 1. After the AP2 completes the measurement of all beam widths, the AP2 obtains channel measurement information between the AP2 and the STAs in the BSS2, and the AP1 obtains channel measurement information between the AP1 and the STAs in the BSS 2.

In the above example, the AP1 and the AP2 receive the uplink frame from the STA by using the same beam width, and the AP1 and the AP2 may not carry the beam width information when exchanging the channel measurement information, so that the overhead during the exchange can be saved. Of course, the AP1 and the AP2 may not receive the uplink frame with the completely uniform beam width. For example, AP1 may receive uplink frame 1 at a beam width of 60 °, while AP2 receives uplink frame 1 at a beam width of 90 °/120 °/150 °, and so on. The AP1/AP2 may sequentially switch the beam widths in order of the beam widths from small to large, may sequentially switch the beam widths in order of the beam widths from large to small, and may switch the beam widths in random order, so long as it is ensured that each beam width of the AP1/AP2 is used for measurement in one measurement period, which is not limited herein. In addition, the AP switches the beam width to be measured and then sends the downlink frame to the STA, and the uplink frame of the STA is received without immediately switching the beam width after sending the downlink frame, so that the AP can be ensured to receive the uplink frame from the STA under the beam width to be measured. Of course, the beam width used by the AP to transmit the downlink frame and the beam width used to receive the uplink frame from the STA may not be exactly the same. For example, the AP may transmit a downlink frame with a wider beam width, and switch to receiving an uplink frame with the beam width to be measured immediately after the transmission.

Fig. 7 is a schematic flow chart of another channel measurement method provided in the present application. Fig. 7 shows that the STA measures channel measurement values between the associated AP and the non-associated AP at different beam widths based on the downlink frame and reports the measurement results to the associated AP. Specifically, AP1 transmits an indication frame to AP2 to inform AP2 that it is ready to transmit a downlink frame for channel measurement. The indication frame may be a trigger frame. After the interval SIFS, the AP1 and the AP2 start to sequentially change the beam width at the same time to transmit the downlink frame. In this case, the downlink frame is a broadcast frame so that both the associated AP and the non-associated AP can receive the downlink frame. The downlink frame may be a beacon (beacon) frame. The time intervals of the downlink frames sent by the AP1 and the AP2 are consistent. STA1-1, STA1-2, STA2-1, and STA2-2 each receive the downlink frames transmitted by AP1 and AP2 to obtain channel measurements with AP1 at different beamwidths and with AP2 at different beamwidths. After each STA obtains the channel measurement, it reports (report) to the associated AP.

The channel measurement value reported by the STA may be an RSSI value or a PL value. For example, the downlink frame sent by the AP includes the sending power of the AP, and the STA may parse the downlink frame to obtain the sending power of the AP, and then obtain the path loss of the transmission link between the AP and the STA under the corresponding beam width according to the sending power and the RSSI value corresponding to the receiving of the downlink frame. The formula is as follows:

In formula I, txP _AP Indicating the transmit power corresponding to the AP transmitting the downlink frame,indicating that the STA receives a beam width a from the AP _BW Received signal strength of downlink frame of downlink transmission, < >>Indicating that AP is at beam width A _BW Path loss between lower and STA.

For example, AP1 and AP2 switch the beam width to 60 °, AP1 transmits beacon frame 1, and AP2 transmits beacon frame 2.STA1-1, STA1-2, STA2-1, and STA2-2 each receive beacon frame 1 from AP1 to obtain an RSSI value with AP1 at a beam width of 60 °, i.eAndand each receiving a beacon frame 2 from the AP2 to obtain an RSSI value with the AP2 at a beam width of 60 °, i.e. +.>And->Each STA calculates a PL value with respect to the AP at a beam width of 60 ° according to equation one. Each of STA1-1 and STA1-2 reports the obtained PL value between AP1 and AP2 in 60 ° beam width and the PL value between AP1 and AP2 in 60 ° beam width. Each of STA2-1 and STA2-2 reports the obtained PL value with AP1 at a beam width of 60 ° and the PL value with AP2 at a beam width of 60 ° to AP2. Each STA receives beacon frames from multiple APs at a time, and is able to obtain multiple channel measurements for these channelsThe measurement values may be reported to the associated AP separately or may be added to a frame and reported to the associated AP together, without limitation.

AP1 and AP2 switch the beam width to 90 °, AP1 transmits beacon frame 3, and AP2 transmits broadcast beacon frame 4.STA1-1, STA1-2, STA2-1, and STA2-2 each receive beacon frame 3 from AP1 to obtain an RSSI value with AP1 at a beam width of 60 °, i.eAnd->And receiving a beacon frame 4 from the AP2 to obtain an RSSI value with the AP2 at a beam width of 60 °, i.e.And->Each STA calculates a PL value with respect to the AP at a beam width of 60 ° according to equation one. Each of STA1-1 and STA1-2 reports the obtained PL value to AP1 with a beam width of 90 ° and the RSSI value to AP2 with a beam width of 90 ° to AP1. Each of STA2-1 and STA2-2 reports the obtained RSSI value with AP1 at a beam width of 90 ° and PL value with AP2 at a beam width of 90 ° to AP2. And so on until AP1 and AP2 have completed all beamwidth measurements.

In the above example, the channel measurement value reported by each STA to the associated AP is the PL value. In other implementations, the STA may not calculate the PL value, but directly report the RSSI value to the associated AP, and the AP may select the beam width based on the RSSI value reported by the STA during cooperative transmission, or may schedule the STA based on the RSSI value reported by the STA.

In the above example, the AP1 and the AP2 use the same beam width to send the downlink frame for measurement to the STA, so that the AP1 and the AP2 may not carry the beam width information when exchanging the channel measurement information, and the overhead during the exchange can be saved. Of course, the AP1 and the AP2 may not transmit the downlink frame for measurement with the completely uniform beam width. For example, AP1 may transmit beacon frame 1 at a beamwidth of 60 °, while AP2 transmits beacon frame 2 at a beamwidth of 90 °/120 °/150 °, and so on.

Fig. 6 and 7 are measurement methods regarding channels between APs and STAs, and a channel measurement method between APs is described below. Beacon frames may be periodically exchanged between AP1 and AP2, with AP1 receiving the beacon frame from AP2 and AP2 receiving the beacon frame from AP1 to obtain a channel measurement between AP1 and AP 2. Specifically, the measurement mode of AP1→ap2 is that AP1 transmits a plurality of beacon frames respectively under different beam widths, and for a plurality of beacon frames transmitted by AP1 under each beam width, AP2 receives respectively under different beam widths, so as to obtain a channel measurement value between AP1 under each beam width and AP2 under each beam width. The measurement method of AP 2-AP 1 is similar, and therefore will not be described in detail here.

For example, AP1 transmits 4 beacon frames with a beam width of 60 °, and AP2 receives the 4 beacon frames with beam widths of 60 °, 90 °, 120 °, and 150 °, respectively, to obtain And->Or->/>And->AP1 transmits 4 beacon frames with a beam width of 90 °, and AP2 receives the 4 beacon frames with beam widths of 60 °, 90 °, 120 °, and 150 °, respectively, to obtainAnd->Or (b)And->And so on until AP1 and AP2 have completed all beamwidth measurements.

Through the measurement, the AP1 may obtain channel measurement information within the BSS1, and partial channel measurement information between the BSS1 and the BSS 2.AP2 may obtain channel measurement information within BSS2, as well as partial channel measurement information between BSS1 and BSS 2. The AP1 and the AP2 may interact with part or all of the channel measurement information obtained by themselves, so that the channel measurement information grasped by each is more comprehensive, and thus a more suitable beam width and STA can be selected based on the channel measurement information in cooperative transmission. For example, through cooperative measurement, the AP1 may obtain channel measurement information 1 between the AP1 and a plurality of STAs in the BSS1 and channel measurement information 2 between the AP2 and a plurality of STAs in the BSS2 under different beam widths. AP2 may obtain channel measurement information 3 between AP2 and multiple STAs within BSS2 and channel measurement information 4 between AP1 and multiple STAs within BSS1 at different beamwidths. The AP1 may transmit the channel measurement information 2 obtained by itself to the AP2, and the AP2 may transmit the channel measurement information 4 obtained by itself to the AP1. Alternatively, the AP1 may transmit both the channel measurement information 1 and the channel measurement information 2 obtained by itself to the AP2, and the AP2 may transmit both the channel measurement information 3 and the channel measurement information 4 obtained by itself to the AP1.

Channel measurement information can also be exchanged between AP1 and AP2 through the switch and the controller. Of course, the AP1 and the AP2 may also exchange channel measurement information through the air interface.

In the preparation stage, the APs in the WLAN system continuously and periodically measure to obtain channel measurement information, in the declaration stage, when the APs in the WLAN system preempt the TXOP, the shared AP preempted to the TXOP can negotiate scheduled STAs and selected beam widths with the shared AP according to the channel measurement information, and the shared AP transmit concurrently under the respective selected beam widths, so that more STAs in the BSS to which the shared AP belongs have a chance to participate in cooperative transmission. And, under the proper wave beam width, the AP can reduce the same-frequency interference as much as possible and increase the antenna gain, thereby improving the system capacity.

Specifically, as shown in fig. 8, fig. 8 is a flow chart of a communication method provided in the present application. The embodiment comprises the following steps:

s801: the shared AP selects a first beam width used by scheduling the shared STA in cooperative transmission, wherein the first beam width is one of at least two adjustable beam widths of the shared AP.

After the shared AP preempts the TXOP, first, a shared STA participating in cooperative transmission is determined according to a resource scheduling algorithm. The sharing AP may schedule multiple STAs as sharing STAs to participate in cooperative transmission in its associated STAs, or may schedule one STA as sharing STA to participate in cooperative transmission in the associated STAs. The sharing STA and the sharing AP both belong to the first BSS.

The resource scheduling algorithm may be a Round Robin (RR), a maximum carrier to interference ratio (Max C/I) algorithm (maximum carrier to interference), a proportional fairness algorithm (proportional fair, PF), or the like.

The antenna of the shared AP has at least two beamwidths that are adjustable, and in the preparation phase, the shared AP has obtained channel measurements between the shared AP and the shared STA at the at least two beamwidths. In the declaration phase, if the shared STA is a single STA, the shared AP selects a first beamwidth from at least two beamwidths of the shared AP according to the beamwidth selection rule and the channel measurement information. The beam width selection rule is, for example, that the shared AP determines, from at least two channel measurement values between the shared AP and the shared STA, a target channel measurement value indicating that the transmission link quality is the best, and the beam width corresponding to the target channel measurement value may be determined as the first beam width used for scheduling the shared STA. When the channel measurement value is an RSSI value or an SINR value, a maximum value of at least two RSSI/SINR values between the shared AP and the shared STA may be determined as a target channel measurement value. When the channel measurement value is a PL value, a minimum value of at least two PL values between the sharing AP and the sharing STA may be determined as the target channel measurement value.

Illustratively, taking the channel measurement as the RSSI value, the shared AP includes four beamwidths of 60 °, 90 °, 120 °, and 150 °. The channel measurement information includes 4 RSSI values between the shared AP and the shared STA, that is, RSSI (60 °), RSSI (90 °), RSSI (120 °), and RSSI (150 °), and if the 4 RSSI values are sorted from large to small as RSSI (90 °) > RSSI (60 °) > RSSI (120 °) > RSSI (150 °), the beam width 90 ° corresponding to RSSI (90 °) can be determined as the beam width of the scheduled shared STA at the time of cooperative transmission.

If the shared STA is multiple STAs, the shared AP needs to schedule the STAs with a beamwidth, and the shared AP may select a beamwidth that can cover the STAs. Specifically, the shared AP may select an appropriate beam width as the first beam width according to the principle that the total throughput is the maximum when each beam width is adopted by the STAs, so as to ensure that the first beam width can cover all the scheduled STAs, thereby ensuring the success rate and the transmission rate of data transmission.

In general, when the distance between the sharing STA and the sharing AP is long, the sharing AP may select a larger beamwidth scheduling sharing AP. When the distance between the shared STA and the shared AP is relatively short, the shared AP may select a smaller beam width to schedule the shared AP, in which case, with respect to a larger beam width, on the one hand, the coverage area of the shared AP becomes smaller, the overlapping coverage area between the shared AP and the shared AP becomes smaller, the non-overlapping coverage area becomes larger, the interference of the shared AP to the STAs with the shared AP and the non-overlapping coverage area of the shared AP becomes smaller, and then there is a chance that more STAs among STAs associated with the shared AP are scheduled to participate in cooperative transmission; on the other hand, under the condition of smaller beam width, the shared AP has larger antenna gain and larger signal strength in the coverage area, and the quality of a transmission link between the shared AP and the shared STA can be improved, so that MCS modulation signals with higher order can be adopted, and the system capacity is increased.

In this embodiment, each channel measurement value in the channel measurement information used by the AP in the declaration stage may be a measurement value obtained by the last channel measurement, or may be an average value or a median value of measurement values obtained by the last N channel measurements. Wherein N is an integer greater than or equal to 2. The channel measurement value obtained from the average value or median value of the measurement values obtained from the N channel measurements is more stable and less affected by the anomaly detection value, and thus the beam width selected based on the channel measurement value is more stable and accurate.

S802: the shared AP sends a cooperative transmission notification to the shared AP, the cooperative transmission notification including cooperative transmission parameters.

After determining the shared STA and the first beam width used in the scheduling, the shared AP sends a cooperative transmission notification carrying cooperative transmission parameters to the shared AP. The cooperative parameters are derived from the shared STA and the first beamwidth. The cooperative transmission notification is, for example, a cooperative spatial multiplexing announcement (coordinated spatial reuse announcement, C-SR-a) frame.

In different cases, the cooperative transmission parameters carried by the cooperative transmission notification are different.

For example, if the candidate shared STA or the candidate second beamwidth of the shared AP is selected by the shared AP according to the cooperative transmission parameters and the channel measurement information, the cooperative transmission parameters include at least two of a first beamwidth selected by the shared AP, an identification of the shared STA, and a first interference limit. The cooperative transmission parameters may further include at least one of a TXOP duration, an identity of a shared AP of the present cooperative transmission, a transmission direction of the shared AP, and the like.

For example, if the shared AP selects the shared STA and/or the candidate second beam width for the shared AP according to the cooperative transmission parameter and the channel measurement information, the cooperative transmission parameter includes at least one of an identification of the candidate shared STA and the candidate second beam width. The cooperative transmission parameters may further include at least one of a TXOP duration, an identity of a shared AP of the present cooperative transmission, a transmission direction of the shared AP, and the like.

The candidate shared STAs are shared APs or STAs meeting interference limitation conditions selected from all associated STAs of the shared APs according to the first beam width, the identification of the shared STAs and channel measurement information. The candidate second beam width is the beam width which is selected by the shared AP or the shared AP according to the shared STA, the first beam width and the channel measurement information and meets the interference limit condition in all adjustable beam widths of the shared AP. The number of candidate shared STAs and candidate second beamwidths may be one or more. The shared AP and the shared AP have interacted with the respective channel measurement information during the preparation phase, so that both the shared AP and the shared AP are able to select candidate shared STAs and candidate second beamwidths for the shared AP. The shared STA selects from among the candidate shared STAs, and the beam width used when scheduling the shared STA selects from among the candidate second beam widths. The manner in which the shared AP selects the candidate shared STA and the candidate second beam width is the same as the manner in which the shared AP selects the candidate shared STA and the candidate second beam width, and the implementation method of the shared AP selecting the candidate second beam width and the candidate second beam width may refer to the following description of the shared AP selecting the candidate shared STA and the candidate second beam width.

The first interference limitation is an interference limitation (tolerable interference limit, TIL) acceptable to a transmission link (hereinafter simply referred to as a first link) between the sharing AP and the sharing STA under the first beamwidth. When the interference suffered by the first link is smaller than the first interference limit, the probability of successfully demodulating the signal by the signal receiver in the first link is higher; when the interference suffered by the first link is greater than or equal to the first interference limit, the error rate may be higher when the signal receiver in the first link demodulates the signal. The first interference limit may be a preset empirical value, or may be calculated according to the first beam width, the shared STA, and the channel measurement information. The way in which the first interference limit is calculated is related to the transmission direction, which will be described in connection with a specific scenario hereinafter.

S803: the shared AP selects a shared STA and a second beam width for cooperative transmission according to the cooperative transmission parameters, wherein the second beam width is one of adjustable beam widths of the shared AP.

In this embodiment, the shared AP may be an AP with an adjustable beam width, and the antenna of the shared AP has at least two adjustable beam widths. After receiving the cooperative transmission notification of the shared AP, the shared AP selects a proper STA from the associated STAs of the shared AP as the shared STA to participate in cooperative transmission according to cooperative transmission parameters in the cooperative transmission notification, and selects the proper beam width from a plurality of adjustable beam widths of the shared AP as a second beam width of the shared AP during cooperative transmission so as to reduce interference between concurrent transmission links during cooperative transmission.

If the candidate shared STA of the shared AP and the candidate second beam width are selected by the shared AP and transmitted to the shared AP through the cooperative transmission notification, the shared AP acquires the cooperative transmission parameters such as the candidate shared STA or the candidate second beam width from the cooperative transmission notification. And the shared AP selects one or more STAs from the candidate shared STAs as the shared AP according to a resource scheduling algorithm, and selects one beam width from the candidate second beam widths corresponding to the shared AP by using the beam width selection rule as the second beam width of the shared AP during cooperative transmission.

If the candidate shared STA and the candidate second beam width of the shared AP are selected by the shared AP itself, the shared AP acquires the cooperative transmission parameters such as the first beam width, the identification of the shared STA, or the first interference limitation from the cooperative transmission notification. And the shared AP takes at least one STA which is selected from all associated STAs of the shared AP and meets the interference limiting condition as a candidate shared STA according to the cooperative transmission parameters and the channel measurement information. And the shared AP selects at least one beam width meeting the interference limit condition from all adjustable beam widths of the shared AP as a candidate second beam width according to the cooperative transmission parameters and the channel measurement information. Then, the shared AP selects one or more STAs from the candidate shared STAs as the shared AP according to the resource scheduling algorithm, and selects one beam width from the candidate second beam widths corresponding to the shared AP as the second beam width of the shared AP for cooperative transmission using the above beam width selection rule.

There are a variety of possible transmission links between the shared AP and the associated STAs of the shared AP, including a transmission link (hereinafter, abbreviated as a second link) that the shared AP forms with each associated STA at each beamwidth, respectively. The shared AP judges whether each second link meets the interference limiting condition or not so as to screen out the second links meeting the interference limiting condition from all the second links. The beam width corresponding to the second link meeting the interference limiting condition is a candidate second beam width, the corresponding STA is a candidate shared STA, and the candidate shared STA and the candidate second beam width have an association relation. That is, when a certain candidate shared STA is selected as a shared STA, it is necessary to select a second beam width from among candidate second beam widths associated with the candidate shared STA. Thus, selecting the shared STA among the candidate shared STAs and selecting the second beamwidth among the candidate second beamwidths associated with the shared STAs can ensure that the transmission link between the shared AP and the shared STAs under the second beamwidth meets the interference constraint condition.

To ensure that the first link can successfully receive and decode the signal during cooperative transmission, the shared AP may determine whether the first interference of each second link to the first link is less than a first interference limit of the first link. A second link that has a first interference to the first link that is less than the first interference limit may be considered a second link that meets the interference limit condition. The first beamwidth that the sharing STA and the sharing AP schedule the sharing STA to use has been determined, and then a first interference limit that the first link can tolerate is determined. The first interference limitation may be calculated by the shared AP and sent to the shared AP through the cooperative transmission notification, or may be calculated by the shared AP according to the first beam width, the identifier of the shared AP and the channel measurement information by sending the first beam width selected by the shared AP and the identifier of the scheduled shared AP to the shared AP through the cooperative transmission notification.

In order to further reduce co-channel interference between concurrent transmission links, the embodiment may further consider interference of the first link to the second link, so as to ensure transmission efficiency and success rate of the second link for cooperative transmission. Specifically, the shared AP determines whether the first interference of each second link to the first link is less than the first interference limit of the first link, and determines whether the second interference limit of each second link is greater than the second interference of the first link to the second link. A second link that has a first interference to the first link that is less than the first interference limit and a second interference that has a second interference limit that is greater than the second interference may be considered a second link that meets the interference limit condition. The second interference limitation may be a preset empirical value, or may be calculated according to the beam width, STA, and channel measurement information corresponding to the second link. The way in which the second interference limit is calculated is related to the transmission direction, which will be described in connection with a specific scenario hereinafter.

The first interference of the second link to the first link, specifically, the interference caused by the signal sent by the signal sender in the second link to the signal receiver of the first link. The second interference of the first link to the second link, specifically, the interference caused by the signal sent by the signal sender in the first link to the signal receiver of the second link. Whether the signal sender, signal receiver is an AP or STA is related to the transmission direction. According to the transmission directions of the first link and the second link, this embodiment may provide three scenarios, that is, the transmission directions of the first link and the second link are both uplink, the transmission directions of the first link and the second link are both downlink, the transmission direction of the first link is uplink, and the transmission direction of the second link is downlink. The method of acquiring the candidate shared STA and the candidate second beamwidth in different scenarios, and the required cooperative transmission parameters are different. When sending the cooperative transmission notification, the shared AP may select, according to the uplink and downlink directions of the first link and the second link, that the corresponding cooperative transmission parameter is carried in the cooperative transmission notification.

Fig. 9a to 9c show several scenarios in which the transmission directions of the first link and the second link are different. Two APs cooperatively transmitting are identified by AP1 and AP2, AP1 associates STA1, and AP2 associates stars. STAx is any associated STA of AP 2. The link between AP1 and STA1 is denoted as a first link and the link between AP2 and star is denoted as a second link. Here, AP1 is taken as a shared AP, STA1 is a shared STA, and AP2 is taken as a shared AP as an example. The link direction is indicated by solid arrows. The source of the interference is indicated by the dashed arrow. In fig. 8, an example is given in which AP1 and AP2 schedule a single STA to participate in cooperative transmission.

In fig. 9a, when the transmission direction of the first link is uplink and the transmission direction of the second link is uplink, and when the AP1 receives the uplink signal sent by the STA1, the STA x sends the uplink signal to the AP2, and the AP1 may receive interference from the STA x. The interference of stars to AP1 at the first beamwidth is the first interference. The first interference is calculated by subtracting the path loss of stars to AP1 at the first beamwidth from the transmit power of stars. The first interference should be less than the first interference limit, as formulated below:

wherein,

in the second, A _Bw1 Is the first beamwidth. TIL1 is the first interference limit, txP _STAx For the transmit power of stars, The path loss for STAx to AP1 at the first beamwidth may be obtained from the channel measurement information. In III, txP _STA1 For the transmit power of STA1, +.>For the path loss from STA1 to AP1 at the first beamwidth, it can be obtained from the channel measurement information, where the minSINR (PER < 10%) is the minimum signal-to-interference-plus-noise ratio required for successful demodulation of the received signal by AP1, i.e. the SINR value such that the bit error rate does not exceed 10%, which is a known parameter. SM (safety margin) is a safety margin, typically taking 0 to 5 decibels (dB).

The transmitting power of the STA may be obtained by the AP through capability negotiation when the STA accesses, or may be an empirical value. Of course, the AP may not acquire the transmit power of the STA. If the channel measurement value is the RSSI value obtained by the first measurement method, then Assuming that the transmit power of the STA is unchanged, i.e., the transmit power of the STA is not adjusted, then equation two may be simplified as:

wherein,for AP1, receiving signal strength of uplink signal from STAx under first beam width,/H>The received signal strength of the uplink signal from STA1 is received for AP1 at the first beamwidth. />And->All are channel measurement values, and can be directly obtained from the channel measurement information.

In formulas two through four, the only variable is STAx. The channel measurement information includes channel measurement values between STA1 and STA x at the first beam width, and the channel measurement values are substituted into equation two or equation four, so that the channel measurement value of the second link satisfying equation two or equation four can be selected. If only the interference of the second link to the first link is considered, the STA x corresponding to the channel measurement value satisfying the equation two or the equation four may be determined as the candidate shared STA. In which case all the adjustable beamwidths of AP2 are candidate second beamwidths.

In cooperative transmission, the first link may also interfere with the second link. For example, when AP2 receives an uplink signal sent by stars and STA1 sends the uplink signal to AP1, AP2 may be interfered by STA 1. STA1 pair beam widthThe interference of the lower AP2 is the second interference. The second interference is calculated by subtracting STA1 from the transmit power of STA1 to the beam width +.>Path loss of AP2 below. If the interference of the first link to the second link is further considered, in addition to the second or fourth equation, the second interference limit of the second link should be satisfied to be greater than the second interference of the first link to the second link. The formula is as follows:

wherein,

in the fifth step, the first step is performed,any of the beamwidths adjustable for AP 2. TIL2 is the second interference limit, txP _STA1 For the transmit power of STA1, +.>For STA1 to beamwidth->The path loss of the AP2 below can be obtained from the channel measurement information. In six, txP _STAx Transmit power for STAx +.>For STAx to Beam Width->The path loss of the AP2 below can be obtained from the channel measurement information. minSINR (PER < 10%) and SM are as defined in equation three. Similarly, if the channel measurement value is the RSSI value obtained by the first measurement method, the fifth expression can be simplified as:

Wherein,for AP2 at beam width +.>Received signal strength of the downstream received uplink signal from STA1,/v>For AP2 at beam width +.>Received signal strength of the downstream received upstream signal from stars. />And->All are channel measurement values, and can be directly obtained from the channel measurement information.

In formulas two to seven, the variables are STAx andSTAx and +.>The channel measurement information includes channel measurement values between the AP2 and the STA1 at each beam width and channel measurement values between the AP2 and the STA x at each beam width, and the channel measurement values are substituted into the equations five (or seven) and 6, so that the second links satisfying the equations five or seven can be selected from all the second links. If the stars corresponding to the second link satisfying the equation five or the equation seven satisfy the equation two or the equation four at the same time, the second link is a second link satisfying the interference constraint condition. And the corresponding STA of the second link meeting the interference limit condition is a candidate shared STA, and the corresponding beam width is a candidate second beam width.

By the above formula, the candidate shared STA and the candidate second beam width in the scenario that the transmission directions of the first link and the second link are both uplink directions can be obtained. Thus, the concurrent transmission link can be made controllable to interfere with each other based on the shared STA selected from the candidate shared STA and the candidate second beamwidth and the second beamwidth. By adjusting the beam width of the AP, the interference between concurrent transmission links can be accurately controlled without adjusting the transmitting power of the STA, and the cooperative transmission throughput rate is improved.

In fig. 9b, the transmission direction of the first link is downlink, the transmission direction of the second link is downlink, and when STA1 receives the downlink signal sent by AP1, AP2 is in beam widthIf a downlink signal is sent to STA2, STA1 may receive the signal from the beam width +.>Interference of AP2 below. The first interference is calculated by beam width +.>The transmit power of AP2 below minus the beam width +.>Path loss from AP2 to STA1 below. The first interference should be less than the first interference limit, as formulated below:

wherein,

in the eighth aspect of the present invention,any of the beamwidths adjustable for AP 2. TIL1 is the first interference limit, txP _AP2 For the transmit power of AP2, +.>For beam width +.>The path loss from AP2 to STA1 below may be obtained from the channel measurement information. In nine, txP _AP1 For the transmit power of AP1, +.>The path loss for AP1 to STA1 at the first beamwidth may be obtained from the channel measurement information. The meaning of other symbols is as in formula three.

The transmit power on the AP side can be determined, then in equation eight, the only variable isThe channel measurement information includes channel measurement values between the AP2 and the STA1 at the first beam width, and the channel measurement values satisfying the equation eight can be selected by substituting the channel measurement values into the equation eight. If only the interference of the second link on the first link is considered, the corresponding +.f. of the channel measurement value satisfying equation eight >May be determined as a candidate second beamwidth. In this case all associated STAs of AP2 may be candidate shared STAs. Of course, in order to ensure the quality of the transmission links of the shared AP and the shared STA, the candidate shared STA corresponding to each candidate second beam width may be screened according to the candidate second beam width and the channel measurement information. For example, when the channel measurement value is an RSSI value, STAs with an RSSI value greater than a threshold value with AP2 at the candidate second beam width may be screened as candidate shared STAs. When the channel measurement value is PL value, STAs with PL value smaller than the threshold value with AP2 under the candidate second beamwidth may be screened as candidate shared STAs.

In cooperative transmission, the first link may also interfere with the second link. For example, when STA2 receives a downlink signal transmitted by AP2 and AP1 transmits the downlink signal to STA1, STA2 may receive interference from AP 1. The interference of the AP1 to the STA2 in the first beam width is the second interference. The second interference is calculated by subtracting the path loss to STA2 from AP1 at the first beamwidth from the transmission power of APA 1. If the interference of the first link to the second link is further considered, in addition to the second or fourth equation, the second interference limit of the second link should be satisfied to be greater than the second interference of the first link to the second link. The formula is as follows:

Wherein,

in ten, A _BW1 Is the first beamwidth. TIL2 is the second interference limit, txP _AP1 For the transmit power of the AP1,the path loss for AP1 to STA2 at the first beamwidth may be obtained from the channel measurement information. In formula eleven, txP _AP2 For the transmit power of AP2, +.>For beam width +.>The path loss from AP2 to star below can be obtained from the channel measurement information. minSINR (PER < 10%) and SM are as defined in equation three.

In formulas eight to eleven, the variables are STAx andSTAx and +.>The channel measurement information includes channel measurement values of each associated STA of the AP1 and the AP2 under the first beam width, and channel measurement values of the AP2 and the STA x under each beam width, and the channel measurement values are substituted into formulas eight to eleven, so that second links satisfying formula ten can be selected from all the second links. And if the beam width corresponding to the second link meeting the formula ten meets the formula eight at the same time, the second link is a second link meeting the interference limiting condition. The beam width corresponding to the second link meeting the interference limitation condition is the candidate second beam width, and the corresponding STA is the candidate shared STA.

By the above formula, the candidate shared STA and the candidate second beam width in the scenario that the transmission directions of the first link and the second link are both downlink directions can be obtained. Thus, the concurrent transmission link can be made controllable to interfere with each other based on the shared STA selected from the candidate shared STA and the candidate second beamwidth and the second beamwidth. By adjusting the beam width of the AP, the interference between the concurrent transmission links can be accurately controlled even without adjusting the transmission power of the AP, and even the antenna gain may be increased, thereby improving the cooperative transmission throughput.

In fig. 9c, the transmission direction of the first link is uplink, the transmission direction of the second link is downlink, and when the AP1 receives the uplink signal sent by the STA1 in the first beam width, the AP2 is in the beam widthDownstream to STA2, AP1 may be subject to interference from AP 2. The first interference is calculated by beam width +.>The transmit power of AP2 below minus the beam width +.>Path loss from AP2 to STA1 below. The first interference should be less than the first interference limit, as formulated below:

wherein,

/>

twelve, A _BW1 For a first beam-width of the beam,any of the beamwidths adjustable for AP 2. TIL1 is the first interference limit, txP _AP2 For the transmit power of AP2, +.>For beam width +.>The path loss from AP2 below to AP1 at the first beamwidth may be obtained from the channel measurement information. In thirteen, txP _AP2 Is the transmit power of AP 2. The meaning of other symbols is as in formula three.

In twelve, the variables areAnd TxP _AP2 . The channel measurement information includes channel measurement values of the AP2 at the first beam width and the AP2 at each beam width, and the channel measurement values are substituted into twelve to obtain the beam widthMaximum transmit power of the lower AP 2. If the beam width +. >The maximum transmission power of the lower AP2 is greater than the lower transmission power limit of the AP2, the beam width +.>Is a candidate second beamwidth.

In the case where the transmission direction of the first link is uplink and the transmission direction of the second link is downlink, only the interference of the second link to the first link may be considered because the interference between STAs is not measurable. In this case all associated STAs of AP2 may be candidate shared STAs. Of course, in order to ensure the quality of the transmission links of the shared AP and the shared STA, the candidate shared STA corresponding to each candidate second beam width may be screened according to the candidate second beam width and the channel measurement information. For example, when the channel measurement value is an RSSI value, STAs with an RSSI value greater than a threshold value with AP2 at the candidate second beam width may be screened as candidate shared STAs. When the channel measurement value is PL value, STAs with PL value smaller than the threshold value with AP2 under the candidate second beamwidth may be screened as candidate shared STAs.

The method for selecting the shared STA and the second beam width is described above by taking the example that the shared AP is an AP with adjustable beam width as an example, however, the shared AP may not be an AP with adjustable beam width, and the second beam width is the beam width configured by the shared AP.

In the declaration phase, the shared AP determines a shared STA and a first beamwidth for cooperative transmission, and the shared AP determines a shared STA and a second beamwidth for cooperative transmission. In the data transmission stage, the shared AP schedules the shared STA to transmit data under the first beam width, and the shared AP schedules the shared STA to transmit data under the second beam width.

The same TXOP may schedule multiple STAs through OFDMA, and may also invoke multiple STAs through time division multiplexing. The TXOP is divided into a plurality of time slices, the AP schedules one STA to participate in cooperative transmission in each time slice, and the STA scheduling of different time slices is independent.

In this embodiment, the AP measures channel measurement information with an associated STA, a non-associated STA, or an on-channel AP by measuring the channel measurement information with different beamwidths. During cooperative transmission, the shared AP selects a proper beam width from a plurality of beam widths which are adjustable by the shared AP by utilizing channel measurement information to schedule the shared STA, so that the interference to the BSS where the shared AP is located can be reduced as much as possible, and the antenna gain of the shared AP is increased. With reduced interference to the BSS in which the shared AP is located, there can be more STAs in the BSS in which the shared AP is located that have the opportunity to participate in the cooperative transmission. In addition, under the conditions that the antenna gain is increased and the interference between the concurrent transmission links is reduced, the concurrent transmission links can transmit data at a higher rate, so that the system capacity can be improved.

As shown in fig. 10, based on the same technical concept, the present application also provides a communication apparatus 1000, where the communication apparatus 1000 may be any AP (first AP) with adjustable beam width in a WLAN system. In one design, the communication device may include a processing module 1001 and a transceiver module 1002. The processing module 1001 is configured to invoke the transceiver module 1002 to perform a function of receiving and/or transmitting.

The transceiver module 1001 is configured to receive, under at least two beamwidths, uplink signals from an associated STA of a first AP, an associated STA of a second AP, and a signal of the second AP, respectively, so as to obtain first channel measurement information. The second AP is the same-frequency AP as the first AP in the WLAN system.

In one possible implementation, the transceiver module 1001 is configured to receive second channel measurement information from a second AP. Wherein the second channel measurement information includes channel measurement values between the second AP and the first AP and/or associated STAs of the first AP under at least two beamwidths, respectively.

In the cooperative transmission scenario, the communication apparatus 1000 may be a shared AP or a shared AP, or may be an apparatus in the shared AP or the shared AP, or may be an apparatus that can be used in match with the shared AP or the shared AP. In one design, the communication device 1000 may include modules corresponding to each other in a manner of executing the method/operation/step/action performed by or in the shared AP in the above method embodiment, where the modules may be hardware circuits, software, or a combination of hardware circuits and software implementation.

When the communication device 1000 is used to perform a method performed by a shared AP:

the processing module 1001 is configured to select a first beam width used by a scheduling shared STA in cooperative transmission, where the first beam width is one of at least two beam widths that are adjustable for an antenna of a shared AP.

A transceiver module 1002, configured to send a cooperative transmission notification to the shared AP. The cooperative transmission notification includes a cooperative transmission parameter, where the cooperative transmission parameter is obtained according to the shared STA and a first beam width, and the cooperative transmission notification is used to instruct the shared AP to select, according to the cooperative transmission parameter, the shared STA and a second beam width for cooperative transmission, where the second beam width is one of beam widths of the shared AP with adjustable antennas.

In one possible implementation, the transceiver module 1002 is configured to receive signals from the associated STA of the shared AP, and/or the signal of the shared AP under at least two beamwidths, respectively, to obtain channel measurement information.

In one embodiment, when the communications apparatus 1000 is configured to perform a method performed by a shared AP:

a transceiver module 1002, configured to receive a cooperative transmission notification from the second AP. The cooperative transmission notification carries a cooperative transmission parameter, wherein the cooperative transmission parameter is obtained according to a first STA and a first beam width, the first STA is the STA for cooperative transmission selected by a second AP from associated STAs of the second AP, and the first beam width is the first beam width for cooperative transmission selected by the second AP from at least two adjustable beam widths of the second AP.

A processing module 1001, configured to select a second beam width for cooperative transmission from at least two beam widths adjustable by the first AP according to the cooperative transmission parameter and the channel measurement information, and select a second STA for cooperative transmission from the associated STAs. The channel measurement information includes first channel measurement information and second channel measurement information, and the second channel measurement information includes channel measurement values between the second AP and the first AP and/or associated STAs of the first AP under at least two beamwidths, respectively.

In one possible implementation, the cooperative transmission parameter includes an identification of a candidate first STA and/or a candidate second beamwidth, where the candidate first STA and/or the candidate second beamwidth are selected according to the first beamwidth, the second STA, and channel measurement information, the candidate first STA includes at least one STA among associated STAs of the first AP, the candidate second beamwidth includes at least one beamwidth among all adjustable beamwidths of the first AP, and the candidate first STA and/or the candidate second beamwidth meets an interference constraint condition, and the channel measurement information is measured by the second AP and the first AP under different beamwidths.

In one possible implementation, the transmission link between the shared AP and the shared STA under the first beamwidth interferes with the transmission link between the shared AP and the shared STA under the second beamwidth less than a second interference limit of the transmission link between the shared AP and the shared STA under the second beamwidth. Wherein the second interference limit is derived from the channel measurement information.

Fig. 11 shows a communication device 1100 according to an embodiment of the present application, configured to implement the function of the shared AP or the shared AP in the above method. When the function of the shared AP is implemented, the communication device may be the shared AP, a device in the shared AP, or a device that can be used in a matching manner with the shared AP. When implementing the function of the shared AP, the device may be the shared AP, a device in the shared AP, or a device that can be used in match with the shared AP. Wherein the communication device may be a system-on-chip. In the embodiment of the application, the chip system may be formed by a chip, and may also include a chip and other discrete devices. The communication device 1100 includes at least one processor 1102 configured to implement the functions of the shared AP or the shared AP in the method provided in the embodiments of the present application. The communication device 1100 may also include a communication interface 1101. In the present embodiment, the communication interface 1101 may be a transceiver, a circuit, a bus, a module, or other type of communication interface for communicating with other devices over a transmission medium. For example, the communication interface 1101 is used in the apparatus 1100 to communicate with other devices. Illustratively, when the communications apparatus 1100 is a shared AP, the other device can be a shared AP. When the communication device 1100 is a shared AP, the other device may be a shared AP. The processor 1102 transmits and receives frames using the communication interface 1102 and is configured to implement the methods described in the method embodiments above.

The present application also provides a computer-readable storage medium, on which a computer program is stored, which when executed by a computer implements the method described in the above method embodiments.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.

In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, or may be in electrical or other forms.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. With such understanding, all or part of the technical solutions of the present application may be embodied in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (RAM, random access memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Claims

1. A method of communication, the method comprising:

the method comprises the steps that a shared Access Point (AP) selects a first beam width used by a scheduling shared Station (STA) in cooperative transmission, wherein the first beam width is one of at least two adjustable beam widths of the shared AP;

the shared AP sends a cooperative transmission notification to the shared AP, where the cooperative transmission notification includes a cooperative transmission parameter, where the cooperative transmission parameter is obtained according to the shared STA and the first beam width, and the cooperative transmission notification is used to instruct the shared AP to select, according to the cooperative transmission parameter, the shared STA and a second beam width for cooperative transmission, where the second beam width is one of beam widths adjustable by the shared AP.

2. The method of claim 1, wherein the cooperative transmission parameters include at least two of the first beamwidth, an identity of the shared STA, and a first interference limit indicating a maximum interference acceptable to a transmission link between the shared AP and the shared STA at the first beamwidth.

3. The method according to claim 1 or 2, wherein the cooperative transmission parameters include an identity of at least one candidate shared STA and/or at least one candidate second beamwidth, each of the candidate shared STAs and/or the candidate second beamwidths being selected based on the first beamwidth, the shared STA and channel measurement information, each of the candidate shared STAs being an STA of an associated STA of the shared AP, each of the candidate second beamwidths being a beamwidth of all adjustable beamwidths of the shared AP, each of the candidate shared STAs and/or the candidate second beamwidths meeting an interference constraint, the channel measurement information being measured by the shared AP and the shared AP under different beamwidths.

4. A method according to claim 3, wherein said meeting an interference constraint comprises:

the first interference of the second link to the first link is smaller than the first interference limit of the first link, the first link is a transmission link between the shared AP and the shared STA under the first beam width, the second link is a transmission link between the shared AP and the candidate shared STA under the candidate second beam width, and the first interference is obtained according to the channel measurement information.

5. The method of claim 4, wherein the compliance with the interference constraint further comprises:

the second interference limit of the second link is greater than the second interference of the first link to the second link, the second interference being derived from the channel measurement information.

6. The method of claims 1 to 5, wherein the coverage area formed by the shared AP on the horizontal plane is different at different beamwidths.

7. The method according to any one of claims 1 to 6, further comprising:

the shared AP receives signals from the associated STA of the shared AP and/or the signals of the shared AP under the at least two beamwidths, respectively, to obtain channel measurement information.

8. A method of communication, the method comprising:

the first Access Point (AP) receives uplink signals from an associated Station (STA) of the first AP and an associated STA of a second AP and signals of the second AP under at least two beam widths respectively to obtain first channel measurement information.

9. The method of claim 8, wherein the uplink signal comprises an acknowledgement frame.

10. The method according to claim 8 or 9, characterized in that the method further comprises:

the first AP receives second channel measurement information from the second AP, the second channel measurement information including channel measurement values between the second AP and the first AP and/or an associated STA of the first AP under at least two beamwidths, respectively.

11. The method according to claims 8 to 10, characterized in that the method further comprises:

the first AP receives a cooperative transmission notification from the second AP, wherein the cooperative transmission notification carries a cooperative transmission parameter, the cooperative transmission parameter is obtained according to a first STA and a first beam width, the first STA is an STA for cooperative transmission selected by the second AP from associated STAs of the second AP, and the first beam width is a first beam width for cooperative transmission selected by the second AP from at least two adjustable beam widths of the second AP;

The first AP selects a first beam width for cooperative transmission from at least two adjustable beam widths of the first AP and selects a first STA for cooperative transmission from associated STAs of the first AP according to the cooperative transmission parameters and channel measurement information, the channel measurement information comprises the first channel measurement information and second channel measurement information, and the second channel measurement information comprises channel measurement values between the second AP and the first AP and/or the associated STAs of the first AP under at least two beam widths respectively.

12. The method of claim 11, wherein the cooperative transmission parameters include at least two of the first beamwidth, an identity of a first STA, and a first interference limit indicating a maximum interference acceptable to a transmission link between the second AP and the first STA at the first beamwidth.

13. The method according to claim 11 or 12, wherein the interference of the transmission link between the second AP and the first STA under the first beamwidth to the transmission link between the first AP and the second STA under the second beamwidth is smaller than a second interference limit of the transmission link between the first AP and the second STA under the second beamwidth, the second interference limit being derived from the channel measurement information.

14. A communication apparatus, applied to a shared AP, comprising means for performing the steps of the communication method according to any of claims 1 to 7 or 8 to 13.

15. A communication device comprising a processor and a communication interface for communicating with other communication devices, the processor being configured to execute a set of instructions to perform the communication method of any of claims 1-7 or 8-13.

16. A computer readable storage medium comprising instructions which, when run on a computer, cause the computer to perform the communication method of any of claims 1 to 7 or 8 to 13.