Methods, systems, and computer-readable media for multi-user MIMO peer-to-peer transmissions

Abstract

The present disclosure generally relates to multi-user MIMO peer-to-peer transmission. Techniques for peer-to-peer (P2P) transmission in a multi-user (MU) multiple-input multiple-output (MIMO) environment. A first wireless station (STA) including multiple radio antennas identifies channel state information (CSI) related to a connection between the first STA and a wireless access point (AP). The first STA determines connection information related to a MU MIMO P2P connection between the first STA and a second STA. Based on the CSI and the connection information, the first STA generates multiple values related to precoding for the multiple radio antennas. The first STA and the second STA exchange data over the peer-to-peer connection using the multiple values related to precoding.

Description

Technical Field

[0001] The embodiments presented in this disclosure generally relate to wireless communications. More specifically, one or more embodiments disclosed herein relate to peer-to-peer (P2P) transmissions in a multi-user (MU) multiple-input multiple-output (MIMO) environment. Background Art

[0002] In an infrastructure Wi-Fi network, wireless stations (STAs) (e.g., computers, smartphones, tablets, vehicles, Internet of Things (IoT) devices, or any other suitable wireless device) typically use wireless access points (APs) to communicate with other STAs. For example, a STA with data intended for another STA in the same network typically sends that data to its associated AP, which then sends the data to the destination STA. However, if the STAs are within each other's transmission range, these two-hop transmissions can result in wasted channels and inefficient transmission. Instead, peer-to-peer transmissions from the source STA to the destination STA can be more efficient. Summary of the Invention

[0003] According to a first embodiment of the present disclosure, a method is provided, comprising: identifying, at a first wireless station (STA) including multiple radio antennas, channel state information (CSI) related to a connection between the first STA and a wireless access point (AP); determining, at the first STA, connection information related to a multi-user (MU) multiple-input multiple-output (MIMO) peer-to-peer connection between the first STA and a second STA; generating, at the first STA, multiple values related to precoding for the multiple radio antennas based on the CSI and the connection information; and exchanging data on the peer-to-peer connection between the first STA and the second STA using the multiple values related to precoding.

[0004] According to a second embodiment of the present disclosure, a system is provided, including: a processor; and a memory having instructions stored thereon, which, when the instructions are executed on the processor, perform operations including the following: identifying, at a first wireless station (STA) including multiple radio antennas, channel state information (CSI) related to a connection between the first STA and a wireless access point (AP); determining, at the first STA, connection information related to a multi-user (MU) multiple-input multiple-output (MIMO) peer-to-peer connection between the first STA and a second STA; generating, at the first STA, multiple values related to precoding for the multiple radio antennas based on the CSI and the connection information; and exchanging data on the peer-to-peer connection between the first STA and the second STA using the multiple values related to precoding.

[0005] According to a third embodiment of the present disclosure, a non-transitory computer-readable medium having instructions stored thereon is provided, and when the instructions are executed by a processor, operations including the following are performed: identifying channel state information (CSI) related to a connection between a first wireless station (STA) including multiple radio antennas and a wireless access point (AP); determining connection information related to a multi-user (MU) multiple-input multiple-output (MIMO) peer-to-peer connection between the first STA and a second STA at the first STA; generating multiple values related to precoding for the multiple radio antennas at the first STA based on the CSI and the connection information; and exchanging data on the peer-to-peer connection between the first STA and the second STA using the multiple values related to precoding. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order that the manner in which the above-described features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate typical embodiments and are therefore not to be considered limiting; other equally effective embodiments are also contemplated.

[0007] Figure 1 is a block diagram illustrating MU MIMO P2P transmission according to one embodiment.

[0008] Figure 2 An AP and STAs are shown for MU MIMO P2P transmission according to one embodiment.

[0009] Figure 3 MU MIMO P2P transmission with uplink from STA to AP according to one embodiment is shown.

[0010] Figure 4 is a flow chart illustrating MU MIMO P2P transmission with uplink from a STA to an AP according to one embodiment.

[0011] Figure 5 MU MIMO P2P transmission with downlink from AP to STAs according to one embodiment is shown.

[0012] Figure 6 is a flow chart illustrating MU MIMO P2P transmission with downlink from an AP to a STA according to one embodiment;

[0013] Figure 7 MU MIMO P2P transmission with synchronized STA transceivers according to one embodiment is shown;

[0014] Figure 8 is a flow chart illustrating use of full channel state information for MUMIMO P2P transmission with synchronized STA transceivers according to one embodiment;

[0015] Figure 9 is a flow chart illustrating MUMIMO P2P transmission with synchronized STA transceivers using partial channel state information according to one embodiment;

[0016] Figure 10 is a flow chart illustrating MU MIMO P2P transmission between a STA and an AP according to one embodiment.

[0017] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation. DETAILED DESCRIPTION

[0018] Overview

[0019] An embodiment includes a method. The method includes identifying, at a first wireless station (STA) including multiple radio antennas, channel state information (CSI) related to a connection between the first STA and a wireless access point (AP). The method also includes determining, at the first STA, connection information related to a multi-user (MU) multiple-input multiple-output (MIMO) peer-to-peer connection between the first STA and a second STA. The method also includes generating, at the first STA, multiple values related to precoding for the multiple radio antennas based on the CSI and the connection information. The method also includes exchanging data on the peer-to-peer connection between the first STA and the second STA using the multiple values related to precoding.

[0020] An embodiment also includes a system comprising: a processor; and a memory having instructions stored thereon, which, when executed on the processor, perform operations. The operations include: identifying, at a first wireless station (STA) comprising multiple radio antennas, channel state information (CSI) related to a connection between the first STA and a wireless access point (AP). The operations also include: determining, at the first STA, connection information related to a multi-user (MU) multiple-input multiple-output (MIMO) peer-to-peer connection between the first STA and a second STA. The operations also include: generating, at the first STA, multiple values related to precoding for the multiple radio antennas based on the CSI and the connection information. The operations also include: exchanging data on the peer-to-peer connection between the first STA and the second STA using the multiple values related to precoding.

[0021] The embodiment also includes a non-transitory computer-readable medium having instructions stored thereon, which, when executed by a processor, perform operations. The operations include: identifying, at a first wireless station (STA) including multiple radio antennas, channel state information (CSI) related to a connection between the first STA and a wireless access point (AP). The operations also include: determining, at the first STA, connection information related to a multi-user (MU) multiple-input multiple-output (MIMO) peer-to-peer connection between the first STA and a second STA. The operations also include: generating, at the first STA, multiple values related to precoding for the multiple radio antennas based on the CSI and the connection information. The operations also include: exchanging data on the peer-to-peer connection between the first STA and the second STA using the multiple values related to precoding.

[0022] Example Embodiments

[0023] As described above, P2P transmissions between STAs within range of each other can improve efficiency and avoid channel waste. Existing wireless standards (e.g., 802.11be) provide some support for direct links between STAs. For example, P2P transmissions between STAs associated with an AP can use a portion of the transmission opportunity (TXOP) duration allocated to the AP. In an embodiment, the AP can use a trigger message or another suitable message to notify its associated STAs of the allocation. The STAs can then use single-user (SU) transmissions for direct communication between them. This can be referred to as a triggered P2P solution (e.g., the AP triggers the P2P connection between STAs).

[0024] However, the prior art does not take advantage of the MU MIMO capabilities in the network. For example, the prior art does not take advantage of the multiple available antennas on many APs and STAs to improve P2P transmissions. In an embodiment, one or more techniques disclosed herein facilitate P2P MU MIMO transmissions between APs (e.g., using multiple antennas). For example, one or more techniques disclosed herein can be used to identify channel state information (CSI) for connections between APs and STAs and connections between STAs. This CSI can be used by the transmitting device to generate a precoding matrix and by the receiving device to generate an appropriate decoder to facilitate MU MIMO transmissions (e.g., using multiple antennas) while avoiding contention and other potential drawbacks.

[0025] In addition, many WiFi standards include random channel access. In a MU-MIMO environment, the receiver can use CSI to separate packets received from multiple clients. Because pilot signals (e.g., legacy long training fields (L-LTF) or extremely high throughput (EHT)-LTF) are included in each physical layer protocol data unit (PPDU), this CSI information may not be available in advance.

[0026] Furthermore, in some cases, time synchronization between the transmitter and receiver can be used to facilitate MU MIMO transmissions (e.g., as described below with respect to Figure 5-Figure 6 As discussed above. For example, a receiver may not have CSI at the beginning of a transmission (e.g., in the legacy portion of the PPDU). The receiver may treat all combined signals as a single PPDU. Time-aligning the packets may allow the receiver to detect a single PPDU. In an embodiment, time alignment may allow the receiver to estimate the EHT-LTF portion of the PPDU for each client's channel, which has a specific timing schedule and requires alignment of the PPDUs.

[0027] Figure 1 1 is a block diagram 100 illustrating MU-MIMO P2P transmission according to one embodiment. In an embodiment, AP 110 is associated with three STAs: STA 150A, STA 150B, and STA 150C. The AP can coordinate and control downlink transmissions from the AP to each STA 150A-C and uplink transmissions from each STA 150A-C to AP 110. In existing solutions, for example, AP 110 can facilitate communication from STA 150A through AP 110 to STA 150B. STA 150A can send data to AP 110. AP 110 receives the data from STA 150A and forwards the data to STA 150C.

[0028] In an embodiment, STA 150A may alternatively use P2P connection 180 to send data directly to STA 150C. For example, assuming STA 150A and STA 150C are within transmission range, STA 150A may use P2P service 162A to establish P2P connection 180 with STA 150C and transmit data to STA 150C. P2P service 162C in STA 150C may receive the data. P2P service 112 in AP 110 may facilitate the establishment of P2P connection 180 and the transmission of data from STA 150A to STA 150C. For example, P2P service 112 in AP 110 may allocate a portion of its TXOP duration for P2P connection 180 and may provide this allocation to STAs 150A and 150C using a trigger frame.

[0029] As discussed further below, in an embodiment, one or more of STAs 150A-C and AP 110 may include multiple antennas and may support MU MIMO data transmission. For example, AP 110 may include two antennas 120 and 122. STA 150A may include two antennas 170 and 172, STA 150B may include one antenna 174, and STA 150C may include one antenna 176.

[0030] As follows about Figure 3-Figure 9 As discussed further, in an embodiment, the P2P service 112 in the AP 110 may be used to coordinate P2P connections between STAs by using multiple antennas for synchronous transmission and reception. For example, the P2P service 112 in the AP 110 may be used to identify the CSI for the connection between the AP 110 and the STA 150A and the CSI for the connection between the AP 110 and the STA 150C. The P2P service 112 may use the CSI values to generate a precoding matrix for the AP 110 to facilitate synchronous transmission and reception using antennas 120 and 122. Similarly, the P2P service 162A in the STA 150A may use the CSI for the connection between the STA 150A and the AP 110 and the CSI for the P2P connection 180 to generate a precoding matrix for the STA 150A to facilitate synchronous transmission using antennas 170 and 172 (e.g., synchronous transmission from the STA 150A to the AP 110 and from the STA 150A to the STA 150C). This will be discussed below with respect to Figure 3-Figure 9 Further discussion.

[0031] Figure 2 FIG. 1 shows an AP 110 and a STA 150 for MU MIMO P2P transmission according to one embodiment. In an embodiment, the STA 150 corresponds to Figure 1 1. The AP 110 includes a processor 202, a memory 210, and a network component 220. The processor 202 typically retrieves and executes programmed instructions stored in the memory 210. The processor 202 represents a single central processing unit (CPU), multiple CPUs, a single CPU with multiple processing cores, a graphics processing unit (GPU) with multiple execution paths, etc.

[0032] Network components 220 include the components necessary for the AP to interface with the communication network, as described above with respect to Figure 1As discussed. For example, the network component 220 may include: a wired, WiFi, or cellular network interface component and associated software. In addition, the network component includes antennas 222 and 224. In an embodiment, the antennas 222 and 224 are any suitable radio antennas that facilitate wireless communication. For example, the antennas 222 and 224 may be 2.4 GHz antennas, 5 GHz antennas, or any other suitable antennas. The antennas 222 and 224 may be internal (e.g., built-in) antennas, external antennas, or any other suitable antennas. In addition, although two antennas 222 and 224 are shown, the AP 110 may include any suitable number of antennas (e.g., one antenna, or more than two antennas).

[0033] Although the memory 210 is shown as a single entity, the memory 210 may include one or more memory devices (e.g., random access memory (RAM), read-only memory (ROM), flash memory, or other types of volatile and / or non-volatile memory) having memory blocks associated with physical addresses. The memory 210 generally includes program code for performing various functions related to the use of the AP 110. The program code is generally described as various functional "applications" or "modules" within the memory 210, but alternative implementations may have different functions and / or combinations of functions. Within the memory 210, the P2P service 112 facilitates MU MIMO P2P connections between STAs associated with the AP 110. This will be discussed below with respect to Figure 3-Figure 8 Further discussion.

[0034] STA 150 includes a processor 252, memory 260, and network components 270. Processor 252 generally retrieves and executes programmed instructions stored in memory 210. Processor 252 represents a single central processing unit (CPU), multiple CPUs, a single CPU with multiple processing cores, a graphics processing unit (GPU) with multiple execution paths, etc.

[0035] Network components 270 include the components necessary for the AP to interface with the communication network, as described above with respect to Figure 1 As discussed. For example, the network component 220 may include a wired, WiFi, or cellular network interface component and associated software. In addition, the network component includes antennas 272 and 274. In an embodiment, the antennas 272 and 274 are any suitable radio antennas that facilitate wireless communication. For example, the antennas 272 and 274 may be 2.4 GHz antennas, 5 GHz antennas, or any other suitable antennas. The antennas 272 and 274 may be internal (e.g., built-in) antennas, external antennas, or any other suitable antennas. In addition, although two antennas 272 and 274 are shown, the STA 150 may include any suitable number of antennas (e.g., one antenna, or more than two antennas).

[0036] Although the memory 260 is shown as a single entity, the memory 210 may include one or more memory devices (e.g., random access memory (RAM), read-only memory (ROM), flash memory, or other types of volatile and / or non-volatile memory) having memory blocks associated with physical addresses. The memory 260 typically includes program code for performing various functions related to the use of the STA 150. The program code is often described as various functional "applications" or "modules" within the memory 260, but alternative implementations may have different functions and / or combinations of functions. Within the memory 260, the P2P service 162 facilitates MU MIMO P2P connections between the STA 150 and one or more other STAs. This will be discussed below with respect to Figure 3-Figure 8 Further discussion. In an embodiment, the P2P service 162 corresponds to Figure 1 Any of the P2P services 162A-C shown.

[0037] Figure 3 MU MIMO P2P transmission with an uplink from a STA to an AP is shown according to one embodiment. System 300 includes STA 350A, which includes two antennas 370 and 372. STA 350A uses antennas 370 and 372 for MU MIMO transmissions (e.g., uplink transmissions) to AP 310 using wireless connection 382, and for MU MIMO transmissions (e.g., P2P transmissions) to another STA 350C using wireless connection 380. For example, STA 350A can use multiple antennas 370 and 372 to simultaneously transmit to AP 310 and STA 350C. AP 310 includes two antennas 320 and 322.

[0038] Furthermore, in an embodiment, STA 350A may use the CSI information for connection 380 and connection 382 to generate a precoding matrix (e.g., a beamforming matrix) to facilitate MUMIMO communication with AP 310 and STA 350C using antennas 370 and 372. For example, AP 310 may provide CSI for connection 382 to STA 350A in a trigger frame, and STA 350C may provide CSI for connection 380 to STA 350A in a Null Data Packet (NDP) message (e.g., initiated by AP 310). P2P service 362A in STA 350A (e.g., corresponding to Figure 2 The P2P service 162 shown in FIG can use the CSI information for connections 380 and 382 to generate a precoding matrix. This will be discussed below with respect to Figure 4 Further discussion.

[0039] Figure 4 FIG4 is a flow chart 400 illustrating MU MIMO P2P transmission with uplink from STA to AP according to one embodiment. For example, Figure 4 Shown for Figure 3 The MU MIMO P2P transmission technology of the system 300 shown in FIG. This is only an example, and the discussion of Figure 4 The technology is not limited to Figure 3 The system 300 shown in FIG.

[0040] At block 402, a transmitting STA (e.g., STA 350A) receives a trigger frame from an AP (e.g., AP 310). In an embodiment, AP 310 supports orthogonal frequency division multiple access (OFDMA) communication (e.g., using 802.11ax or other suitable wireless protocols). For example, AP 310 can initiate uplink communication from STA 350A by transmitting a suitable trigger frame. As an example, AP 310 can send a trigger-based (TB) PPDU to STA 350A. Furthermore, as described above, in an embodiment, AP 310 can support a triggered P2P solution. For example, AP 310 can trigger P2P connection 380 and allocate a portion of its TXOP duration by transmitting a trigger frame to STA 350A.

[0041] At block 404, the transmitting STA extracts the CSI. For example, a P2P service (e.g., P2P service 362A) in STA 350A may extract the CSI for connection 382 from a trigger frame (e.g., from a TB PPDU) received from AP 310.

[0042] At block 406, the transmitting STA issues a warning to the AP regarding support for MU MIMO P2P. For example, STA 350A may send a message to AP 310 indicating that STA 350A supports MU MIMO P2P. In an embodiment, the transmitting STA includes this indication in a buffer status report (BSR) message. For example, P2P service 362A in STA 350A may transmit a BSR to AP 310 with an indication of MU MIMO P2P support (e.g., a flag or any other suitable field). This is merely an example, and any suitable message may be used.

[0043] At block 408, the AP instructs the receiving STA to transmit CSI to the transmitting STA. In an embodiment, the P2P service in the AP receives a message from the transmitting STA indicating support for MU MIMO P2P. The AP then transmits an instruction to the receiving STA to provide the transmitting STA with CSI for the connection between the transmitting STA and the receiving STA.

[0044] For example, the P2P service 312 in the AP 310 (eg, corresponding to Figure 2 350A. The P2P service 312 (shown) may receive a BSR (or another suitable message) from STA 350A indicating that STA 350A supports MU MIMO. The P2P service 312 may then transmit a message to STA 350C instructing STA 350C to provide CSI for connection 380 between STA 350C and STA 350A to STA 350A (e.g., using antenna 376 in STA 350C). The P2P service in STA 350C (e.g., P2P service 362C) then transmits the CSI for connection 380 to STA 350A. In an embodiment, P2P service 362C transmits a message including the CSI for connection 380 to STA 350A. Alternatively or additionally, the P2P service 362A in STA 350A determines the CSI for connection 380 based on the message transmitted by STA 350C.

[0045] At block 410, the transmitting STA generates a precoding matrix. In an embodiment, the precoding matrix is a beamforming matrix used by the transmitting STA to facilitate MU MIMO transmission using multiple antennas. In addition, in an embodiment, the existing technique for generating the beamforming matrix may take into account the CSI for the connection from the transmitting STA to its two destinations (the AP and the other STA).

[0046] For example, STA 350A receives CSI for two connections: connection 382 with AP 310 and connection 380 with STA 350C. P2P service 362A in STA 350A uses the CSI derived from both AP 310 and STA 350C to generate a beamforming matrix to facilitate transmission to both AP 310 and STA 350C using two antennas 370 and 372. For example, STA 350A can use the beamforming matrix to synchronize transmissions to both AP 310 and STA 350C using two antennas 370 and 372. In an embodiment, P2P service 362A uses any suitable technique (e.g., any suitable existing technique) for generating a beamforming matrix for MU MIMO transmission.

[0047] Figure 5MU MIMO P2P transmission with downlink from AP to STA according to one embodiment is shown. System 500 includes AP 510 and two STAs 550A and 550C. In an embodiment, STA 550C includes two antennas 574 and 576. STA 550C receives simultaneous transmissions from AP 510 (e.g., downlink transmissions via connection 582) and simultaneous transmissions from STA 550A (e.g., P2P transmissions via connection 580).

[0048] In an embodiment, STA 550C receives a combined PPDU from AP 510 and STA 550A. To facilitate receiving the combined PPDU, STA 550C may receive transmissions from AP 510 and STA 550A at synchronized times. In an embodiment, STA 550A may synchronize its transmission timing with AP 510. For example, STA 550A may use a trigger frame (e.g., a TB PPDU) received from AP 510 to synchronize its clock with AP 510. STA 550A may then use this synchronized clock to synchronize transmissions to STA 550C. This will be discussed below with respect to Figure 6 Further discussion.

[0049] Figure 6 FIG6 is a flow chart 600 illustrating MU MIMO P2P transmission with downlink from an AP to a STA according to one embodiment. For example, Figure 6 Shown for Figure 5 The technology of MU MIMO P2P transmission of system 500 is shown in FIG. This is only an example, and the discussion is about Figure 6 The technology is not limited to Figure 5 The system 500 shown in FIG.

[0050] At block 602, the transmitting STA receives a trigger frame from the AP. For example, as described above, AP 510 supports OFDMA communication (e.g., using 802.11ax or other suitable wireless protocols). AP 510 can initiate communication from STA 550A by transmitting a suitable trigger frame (e.g., a TBPPDU). As another example, AP 510 can support a triggered P2P solution, in which AP 510 triggers P2P connection 580 and allocates a portion of its TXOP by transmitting a trigger frame to STA 550A. In an embodiment, STA 550A receives a trigger frame from AP 510.

[0051] At block 604, the transmitting STA adjusts its clock offset based on the trigger frame. In an embodiment, the transmitting STA may use the received trigger frame to identify the carrier frequency offset (CFO). The transmitting STA may calculate the clock offset based on the identified CFO to synchronize transmissions between the transmitting STA and the AP with transmissions between other STAs and the AP.

[0052] For example, STA 550A may receive a trigger frame from AP 510 (e.g., a trigger frame transmitted using P2P service 512 in AP 510). AP 510 includes antenna 520. STA 550A includes antenna 570. P2P service 562A in STA 550A (e.g., corresponding to Figure 2 562A) can use the received trigger frame to identify the CFO from the AP. P2P service 562A can then calculate the clock offset between AP 510 and STA 550A. P2P service 562A can use this calculated clock offset to synchronize the transmission time from AP 510 and STA 550A to STA 550C (and P2P service 562C). In an embodiment, the synchronized transmissions are not sent at exactly the same time, but rather within a small tolerance (e.g., plus or minus 400 Hz).

[0053] At block 606, the receiving STA receives the combined transmission. In an embodiment, the receiving STA receives time-synchronized combined transmissions from the AP and another STA. For example, STA 550C receives combined transmissions from AP 510 and STA 550A. As described above, STA 550A synchronizes its transmissions with AP 510 (e.g., using a trigger frame received from the AP), causing STA 550C to receive synchronized transmissions.

[0054] Figure 7 MU MIMO P2P transmission with synchronized STA transceivers is shown according to one embodiment. System 700 includes an AP 710 and three STAs 750A-C. AP 710 includes two antennas 720 and 722. STA 750A includes antenna 770. STA 750B includes antenna 772. STA 750C includes two antennas 774 and 776.

[0055] In an embodiment, system 700 shows two pairs of simultaneous transmissions. AP 710 transmits to STA 750C using downlink connection 782 and transmits to STA 750B using downlink connection 784. STA 750A transmits to STA 750B using P2P connection 786 and transmits to STA 750C using P2P connection 780. In an embodiment, the following discussion of Figure 8 and Figure 9 The technology allows STA 750A to establish P2P connections 780 and 786 (e.g., with other STAs 750C and 750B) without affecting the downlink connections 782 and 784 from AP 710. For example, as discussed further below, STA 750A can establish P2P connections 780 and 786 while causing very little interference to the downlink connections 784 and 782 from AP 710 to STAs 750B and 750C. STAs 750B and 750C can extract data from transmissions from AP 710 while synchronously receiving transmissions from STA 750A using P2P connections 780 and 786.

[0056] Figure 8 FIG8 is a flow chart 800 illustrating the use of full channel state information for MUMIMO P2P transmission with synchronized STA transceivers according to one embodiment. For example, Figure 8 Shown in Figure 7 The system 700 shown uses full channel state information for MU MIMO P2P transmission with synchronized STA transceivers. This is only an example and is not intended to be used with respect to Figure 8 The technologies discussed are not limited to Figure 7 System 700 is shown.

[0057] In an embodiment, the P2P service 712 in the AP 710 (eg, corresponding to Figure 2 The P2P service 112 shown in FIG. 110 uses the full channel state information to determine an appropriate precoding matrix (e.g., a beamforming matrix) to transmit data to STAs 750B and 750C using antennas 720 and 722. Similarly, the P2P service 762C in STA 750C (e.g., corresponding to Figure 2 780) uses the full channel state information to determine an appropriate decoder (e.g., a minimum mean square equalizer (MMSE) decoder) to receive data from AP 710 and STA 750A using antennas 774 and 776. For example, P2P service 712 in AP 710 can use the CSI for downlink connections 782 and 784 to determine the beamforming matrices for its antennas 720 and 722. P2P service 762C in STA 750C uses the channel states of downlink connection 782 and P2P connection 780 to determine the decoders for its antennas 774 and 776.

[0058] However, in an embodiment, it is difficult for the P2P service 762C in the STA 750C to determine the CSI for the P2P connection 780. In an embodiment, Figure 8A technique is shown for determining CSI for a P2P connection 780 at a STA 750C and using the CSI to generate a precoding matrix (e.g., using full channel state information). Figure 9 Techniques for generating a precoding matrix for a STA 750C without determining the CSI for the P2P connection 780 (eg, using partial channel state information) are discussed.

[0059] At block 802, the AP and the receiving STA use a trigger frame to determine CSI for a downlink connection. In an embodiment, the P2P service 712 in the AP 710 (e.g., corresponding to Figure 2 11) can use the trigger frame transmitted to STAs 750B and 750C to determine the CSI for downlink connections 784 and 782. For example, as described above, AP 710 supports OFDMA communication (e.g., using 802.11ax or other suitable wireless protocols). AP 710 can initiate communication with STAs 750B and 750C by transmitting a suitable trigger frame (e.g., a TB PPDU). As another example, AP 710 can support a triggered P2P solution, wherein AP 710 triggers P2P connections 780 and 786 by transmitting a trigger frame to STA 750A and allocates a portion of its TXOP.

[0060] AP 710 may use these trigger frames to determine CSI for downlink connections 784 and 782. Additionally, P2P service 762B in STA 750B and P2P service 762C in STA 750C may use the trigger frames transmitted by AP 710 to determine CSI for respective downlink connections 784 and 782.

[0061] At block 804, the receiving STA uses the first P2P transmission to determine the P2P CSI. For example, as described above, STA 750C uses the CSI for downlink connection 782 and P2P connection 780 to determine the appropriate decoder (e.g., MMSE decoder). STA 750C determines the CSI for downlink connection 782 based on the trigger frame transmitted by AP 710. However, in Figure 8In the illustrated embodiment, STA 750C also requires CSI for P2P connection 780. In an embodiment, STA 750C uses the transmission from STA 750A (e.g., the first transmission) to determine the CSI for P2P connection 780. In an embodiment, this requires STA 750C to initialize the decoder using legacy information (e.g., default information, or from a previously deployed implementation). After STA 750C receives the transmission from STA 750A, STA 750C is able to determine the CSI for P2P connection 780 and determine an appropriate updated decoder (e.g., an appropriate MMSE decoder).

[0062] At block 806, the AP uses the downlink channel state to determine a precoding matrix (e.g., a beamforming matrix). For example, the AP 710 may use the CSI for downlink connections 784 and 782 (as discussed above with respect to block 802) to determine the beamforming matrix for the two antennas 720 and 722.

[0063] At block 808, the receiving STA determines a decoder based on the downlink channel state and the P2P channel state. For example, as discussed above with respect to block 804, STA 750C may use the trigger frame from AP 710 to determine the CSI for downlink connection 782. STA 750C may use the transmission (e.g., the first transmission) from STA 750A to determine the CSI for P2P connection 780. STA 750C may then use the CSI for downlink connection 782 and P2P connection 780 to determine the appropriate decoder for its antennas 774 and 776.

[0064] Figure 9 FIG. 9 is a flow chart illustrating the use of partial channel state information for MUMIMO P2P transmission with synchronized STA transceivers according to one embodiment. For example, Figure 9 Shown in Figure 7 The system 700 shows the use of partial channel state information with synchronized STA transceivers for MU MIMO P2P transmission. This is only an example and is not intended to be used with respect to Figure 9 The technologies discussed are not limited to Figure 7 System 700 is shown.

[0065] As described above, in an embodiment, it is difficult for the STA 750C to determine the CSI for the P2P connection 780 . Figure 8 STA 750C is shown using transmissions over P2P connection 780 to determine CSI for P2P connection 780. In an embodiment, Figure 9 and Figure 8 The difference is that Figure 9MU MIMO P2P transmission is illustrated without requiring the STA 750C to determine the CSI for the P2P connection 780 .

[0066] At block 902, the AP and the receiving STA use a trigger frame to determine CSI for the downlink connection. In an embodiment, this is similar to block 802 discussed above. For example, the P2P service 712 in the AP 710 can transmit a trigger frame to the STA 750B and the STA 750C, and can use these trigger frames to determine CSI for the downlink connections 784 and 782. In addition, the P2P service 762B in the STA 750B and the P2P service 762C in the STA 750C can use the trigger frame transmitted by the AP 710 to determine the CSI for the respective downlink connections 784 and 782.

[0067] At block 904, the AP uses the downlink channel state to determine a precoding matrix (e.g., a beamforming matrix). In an embodiment, this is similar to block 806 discussed above. For example, AP 710 can use the CSI for downlink connections 784 and 782 (as discussed above with respect to block 802) to determine the beamforming matrix for the two antennas 720 and 722.

[0068] At block 906, the receiving STA determines a decoder based on the interference (e.g., measured interference) from the transmitting STA. CSI is one example of connection information related to a P2P connection. Interference data related to a P2P connection (e.g., an interference covariance matrix) is another example of connection information. As described above, Figure 9 In the illustrated embodiment, the receiving STA does not use the CSI for the P2P connection to determine the decoder. In an embodiment, instead, the receiving STA uses the measured interference data from the transmitting STA.

[0069] For example, STA 750C does not receive CSI for P2P connection 780. Instead, STA 750C uses measured interference data (e.g., interference covariance matrix) from STA 750A to determine a decoder. For example, STA 750C may use the interference covariance matrix from STA 750A to determine a decoder (e.g., MMSE decoder) for its antennas 774 and 776.

[0070] Alternatively or additionally, STA 750C may further use the CSI for the P2P connection 780. For example, STA 750C may use the interference covariance matrix from STA 750A to set the initial value of the decoder (e.g., MMSE decoder). STA 750C may then determine the CSI for the P2P connection 780 based on the first transmission from STA 750A using the P2P connection 780 and may update the decoder.

[0071] Figure 10 1000 is a flowchart illustrating MU MIMO P2P transmission between a STA and an AP according to one embodiment. At block 1002, a P2P service (e.g., in a STA) identifies CSI for a connection between the STA and the AP. For example, as described above with respect to Figure 3 and about Figure 4 As discussed above with respect to blocks 402 and 404, the P2P service 362A in the STA 350A may identify the CSI for the connection 382 between the STA 350A and the AP 310. As another example, as discussed above with respect to Figure 7 and about Figure 8 and Figure 9 As discussed in blocks 802 and 902 of FIG. 7 , the P2P service 762C in the STA 750C may identify the CSI for the connection 782 between the STA 750C and the AP 710 .

[0072] At block 1004, the P2P service determines connection information for the MU MIMO P2P connection between the STAs. For example, as described above with respect to Figure 3 and about Figure 4 As discussed above with respect to blocks 406 and 408, the P2P service 362A in STA 350A may determine the CSI for the MU MIMO P2P connection 380 between STA 350A and STA 350C. As another example, as discussed above with respect to Figure 7 and about Figure 8 As discussed above with respect to block 804 in FIG. 8 , the P2P service 762C may determine the CSI for the MUMIMO P2P connection 780 between STA 750A and STA 750C. As another example, as discussed above with respect to Figure 7 and about Figure 9 As discussed at block 906 in FIG. 8 , the P2P service 762C may determine interference data (eg, an interference covariance matrix) for the MU MIMO P2P connection 780 between the STA 750A and the STA 750C.

[0073] At block 1006, the P2P service uses the CSI and connection information to generate precoding related values. For example, as described above with respect to Figure 3 and about Figure 4 As discussed above with respect to block 410 in FIG. 4 , the P2P service 362A in STA 350A may use the CSI for connections 380 and 382 to generate a precoding matrix. As another example, as discussed above with respect to Figure 7 and about Figure 8 As discussed in block 808 of FIG. , the P2P service 762C in STA 750C may use the CSI for connections 780 and 782 to determine a decoder (e.g., an MMSE decoder). As another example, as discussed above with respect to Figure 7 and about Figure 9 As discussed at block 906 in FIG. 8 , the P2P service 762C in the STA 750C may use the CSI for the connection 782 and the interference data for the connection 780 to determine a decoder (eg, an MMSE decoder).

[0074] At block 1008, the P2P service uses the precoding-related values to exchange data via the P2P connection. Figure 3 As shown, STA 350A may transmit data over connection 380 using antennas 370 and 372 and the precoding matrix generated at block 1006. As another example, as described above with respect to Figure 7 As illustrated, STA 750C may receive data over connection 780 using antennas 774 and 776 and the decoder determined at block 1006 .

[0075] In this disclosure, reference is made to various embodiments. However, the scope of this disclosure is not limited to the specifically described embodiments. On the contrary, any combination of the described features and elements, whether or not related to different embodiments, is for the purpose of implementing and practicing the envisioned embodiments. In addition, when the elements of an embodiment are described in the form of "at least one of A and B", it will be understood that embodiments comprising element A alone, element B alone, and elements A and B are all considered. In addition, although some embodiments disclosed herein can achieve advantages over other possible solutions or prior art, whether a particular advantage is achieved by a given embodiment does not limit the scope of this disclosure. Therefore, the various aspects, features, embodiments and advantages disclosed herein are merely illustrative and are not considered to be elements or limitations of the appended claims unless expressly stated in (one or more) claims. Similarly, reference to "the present invention" should not be interpreted as a summary of any inventive subject matter disclosed herein and should not be considered to be elements or limitations of the appended claims unless expressly stated in (one or more) claims.

[0076] As will be appreciated by those skilled in the art, the embodiments disclosed herein may be embodied as systems, methods, or computer program products. Therefore, the embodiments may take the form of complete hardware embodiments, complete software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects, which may be collectively referred to herein as "circuits," "modules," or "systems." Furthermore, the embodiments may take the form of a computer program product contained in one or more computer-readable media having a computer-readable program code embodied therein.

[0077] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0078] The computer program code for performing the operation of the embodiments of the present disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages (such as Java, Smalltalk, C++, etc.) and traditional procedural programming languages (such as "C" programming language or similar programming languages). The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider through the Internet).

[0079] Various aspects of the present disclosure are described herein with reference to the flowchart illustrations and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments proposed in the present disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and the combination of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that the instructions executed by the processor of the computer or other programmable data processing device create a means for implementing the function / action specified in the (one or more) blocks of the flowchart illustrations and / or block diagrams.

[0080] These computer program instructions may also be stored in a computer-readable medium, which may instruct a computer, other programmable data processing apparatus, or other device to operate in a specific manner so that the instructions stored in the computer-readable medium produce an article of manufacture, including instructions for implementing the functions / actions specified in (one or more) blocks of the flowchart illustration and / or block diagram.

[0081] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other device to produce a computer-implemented process, such that the instructions executed on the computer, other programmable data processing apparatus, or other device provide a process for implementing the functions / actions specified in the flowchart illustration and / or block(s) of the block diagram.

[0082] The flowchart illustrations and block diagrams in the figure illustrate the architecture, function and operation of the possible implementation of the system, method and computer program product according to various embodiments. In this regard, each block in the flowchart illustration or block diagram can represent a module, segmentation or code portion, which includes one or more executable instructions for realizing (one or more) specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the block may not appear in the order marked in the figure. For example, depending on the function involved, the two blocks shown in succession can actually be performed substantially simultaneously, or sometimes these blocks can be performed in reverse order. It will also be noted that each block in the block diagram and / or flowchart illustration, and the combination of the blocks in the block diagram and / or flowchart illustration can be realized by a combination of a system based on dedicated hardware or dedicated hardware and computer instructions that performs a specified function or action.

[0083] In view of the foregoing, the scope of the present disclosure is determined by the following claims.

Claims

1. A method for multi-user (MU) multiple-input multiple-output (MIMO) peer-to-peer transmission, comprising: identifying, at a first wireless station (STA) comprising a plurality of radio antennas, channel state information (CSI) related to a connection between the first STA and a wireless access point (AP); determining, at the first STA, connection information related to a MU MIMO peer-to-peer connection between the first STA and a second STA, wherein the connection information includes second CSI related to the peer-to-peer connection, the second CSI being determined at the second STA and sent by the second STA to the first STA in response to receiving an instruction from the AP to provide the second CSI to the first STA, wherein the instruction is sent by the AP to the second STA in response to receiving a message from the first STA indicating that the first STA supports MU MIMO; generating, at the first STA, a plurality of values related to precoding for the plurality of radio antennas based on the CSI and the connection information; and Data is exchanged over the peer-to-peer connection between the first STA and the second STA using the plurality of values related to precoding.

2. The method according to claim 1, wherein The multiple values related to precoding include a precoding matrix, and wherein the first STA uses the precoding matrix to transmit data to the second STA through the peer connection, and uses the precoding matrix to transmit data to the AP using the connection between the first STA and the AP.

3. The method according to claim 2, wherein: The first STA determines the CSI based on a trigger frame received from the AP.

4. The method according to claim 1, wherein The plurality of values related to precoding include a decoder, and wherein the first STA receives data from the second STA through the peer connection using the decoder, and receives data from the AP using the connection between the first STA and the AP using the decoder.

5. The method according to claim 4, wherein The connection information related to the peer-to-peer connection includes interference information.

6. The method according to claim 5, wherein: The interference information includes a covariance matrix.

7. The method according to claim 4, wherein: The first STA determines the second CSI based on a data transmission received from the second STA using the peer-to-peer connection.

8. The method according to claim 4, wherein: The AP includes a second plurality of antennas, the method further comprising: A precoding matrix associated with the second plurality of antennas is determined at the AP based on the CSI associated with the connection between the AP and the first STA.

9. The method according to claim 8, wherein Determining the precoding matrix is also based on third CSI related to a connection between the AP and a third STA.

10. The method according to claim 1, further comprising: Based on a trigger frame received from the AP, a clock offset for receiving data using the multiple antennas is adjusted at the first STA.

11. A system for multi-user (MU) multiple-input multiple-output (MIMO) peer-to-peer transmission, comprising: processor; as well as A memory having instructions stored thereon, which, when executed on the processor, perform operations including: identifying, at a first wireless station (STA) comprising a plurality of radio antennas, channel state information (CSI) related to a connection between the first STA and a wireless access point (AP); determining, at the first STA, connection information related to a MU MIMO peer-to-peer connection between the first STA and a second STA, wherein the connection information includes second CSI related to the peer-to-peer connection, the second CSI being determined at the second STA and sent by the second STA to the first STA in response to receiving an instruction from the AP to provide the second CSI to the first STA, wherein the instruction is sent by the AP to the second STA in response to receiving a message from the first STA indicating that the first STA supports MU MIMO; generating, at the first STA, a plurality of values related to precoding for the plurality of radio antennas based on the CSI and the connection information; and Data is exchanged over the peer-to-peer connection between the first STA and the second STA using the plurality of values related to precoding.

12. The system according to claim 11, wherein The multiple values related to precoding include a precoding matrix, and wherein the first STA uses the precoding matrix to transmit data to the second STA through the peer connection, and uses the precoding matrix to transmit data to the AP using the connection between the first STA and the AP.

13. The system according to claim 12, wherein: The first STA determines the CSI based on a trigger frame received from the AP.

14. The system according to claim 11, wherein: The plurality of values related to precoding include a decoder, and wherein the first STA receives data from the second STA through the peer connection using the decoder, and receives data from the AP using the connection between the first STA and the AP using the decoder.

15. The system according to claim 14, wherein: The connection information related to the peer-to-peer connection includes interference information.

16. A non-transitory computer-readable medium having stored thereon instructions that, when executed by a processor, perform operations comprising: identifying, at a first wireless station (STA) comprising a plurality of radio antennas, channel state information (CSI) related to a connection between the first STA and a wireless access point (AP); Determining, at the first STA, connection information related to a multi-user (MU) multiple-input multiple-output (MIMO) peer-to-peer connection between the first STA and a second STA, wherein The connection information includes second CSI related to the peer-to-peer connection, the second CSI being determined at the second STA and sent by the second STA to the first STA in response to receiving an instruction from the AP to provide the second CSI to the first STA, wherein the instruction is sent by the AP to the second STA in response to receiving a message from the first STA indicating that the first STA supports MU-MIMO; generating, at the first STA, a plurality of values related to precoding for the plurality of radio antennas based on the CSI and the connection information; as well as Data is exchanged over the peer-to-peer connection between the first STA and the second STA using the plurality of values related to precoding.

17. The computer-readable medium of claim 16, wherein: The multiple values related to precoding include a precoding matrix, and wherein the first STA uses the precoding matrix to transmit data to the second STA through the peer connection, and uses the precoding matrix to transmit data to the AP using the connection between the first STA and the AP.

18. The computer-readable medium of claim 17, wherein: The first STA determines the CSI based on a trigger frame received from the AP.

19. The computer-readable medium of claim 16, wherein: The plurality of values related to precoding include a decoder, wherein the first STA receives data from the second STA through the peer connection using the decoder, and receives data from the AP using the decoder using the connection between the first STA and the AP, and wherein the connection information related to the peer connection includes interference information.

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