Coordinated spatial multiplexing

Abstract

A technical solution of an access point (AP) is disclosed, the AP comprising a processing device and a transceiver. The processing device can receive, at the AP from a station (STA), information about an interference path between the STA and the AP; select, at the AP based on the information about the interference path between the STA and the AP, a transmit power; and determine, at the AP based on the transmit power, a transmission type, wherein the transmission type comprises one or more of a spatial multiplexing transmission or a spatial nulling transmission. The transceiver can transmit, from the AP to the STA, a transmission based on the transmission type.

Description

[0001] Related applications This application claims priority to U.S. Provisional Application No. 63 / 581,656, filed September 9, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to wireless communications, and more specifically to improving latency and throughput of wireless local area networks (LANs) by coordinating spatial multiplexing. Background Technology

[0003] Unless otherwise stated herein, the materials described herein are not prior art as claimed in this application and should not be considered prior art simply because they are included in this section.

[0004] An access point (AP) is a network hardware device that allows other Wi-Fi networks to connect to it. ® The device connects to a wired network. As a standalone device, the AP can be connected to a router via a wired connection; in a wireless router, the AP can also be an integrated component of the router itself. Currently, various wireless data standards have been introduced for wireless access points and wireless routers, such as 802.11a, 802.11b, 802.11g, and 802.11n (Wi-Fi). ® 4) 802.11ac (Wi-Fi) ® 5) 802.11ax (Wi-Fi) ® 6) etc.

[0005] The subject matter claimed in this disclosure is not limited to implementations that address any defects, nor is it limited to operation only in the aforementioned environments. Rather, this background art is provided merely to illustrate one example technical field in which certain examples described in this disclosure may be implemented. Summary of the Invention

[0006] An access point (AP) may include a processing device and a transceiver. The processing device may receive information about interference paths between a station (STA) and the AP from the AP; select a transmit power at the AP based on the information about the interference paths between the STA and the AP; and determine a transmission type at the AP based on the transmit power, wherein the transmission type includes one or more of spatial multiplexing transmission or spatial nulling transmission. The transceiver may transmit a transmission from the AP to the STA based on the transmission type.

[0007] A station (STA) may include a processing unit and a transceiver. The processing unit may receive probe packets at the STA from access points (APs) that are not previously associated with the STA; and calculate coordinated spatial reuse (C-SR) feedback at the STA. The transceiver may send the C-SR feedback to the AP.

[0008] A coordination device may include a processing unit and a transceiver. The processing unit may send a joint probe process trigger from the coordination device to a first access point (AP); send the joint probe process trigger from the coordination device to a second AP; receive a first probe feedback from the first AP at the coordination device; receive a second probe feedback from the second AP at the coordination device; and determine one or more of the following at the coordination device: the transmit power of one or more of the first AP or the second AP; or a spatial null of one or more of the first AP or the second AP.

[0009] The objectives and advantages of the various embodiments will be realized and achieved through the elements, features and combinations specifically pointed out in the claims.

[0010] The foregoing overview and subsequent details are illustrative and do not constitute a limitation on the claimed invention. Attached Figure Description

[0011] The embodiments will now be described and illustrated in more detail with reference to the accompanying drawings, wherein: Figure 1 An example of two overlapping wireless LANs (e.g., a basic service set, BSS) is shown.

[0012] Figure 2 An example of a packet sequence for probing two access points (APs) and two stations (STAs) associated with each AP using Coordinated Spatial Reuse (C-SR) feedback is shown.

[0013] Figure 3 An example of control for reducing nulling disturbances is shown.

[0014] Figure 4 An example of a managed network (e.g., an extended service set (ESS) with two BSSs and a central coordinating device) is shown.

[0015] Figure 5 An example of a managed network (e.g., an Extended Service Unit (ESS) with two BSSs and a central coordinating device located in one of the access points) is shown.

[0016] Figure 6 An example of a packet sequence used for joint probe and the triggered Coordinated Spatial Reuse (C-SR) transmission is shown in an Extended Service Unit (ESS).

[0017] Figure 7 The diagram shows the rate ranges for two users, comparing the rate point of joint optimization (optimal total rate) with the optimal rate for the primary user minus the penalty value (e.g., ...). =3dB).

[0018] Figure 8 An example communication system suitable for spatial multiplexing is shown.

[0019] Figure 9 The processing flow for spatial multiplexing at the access point is shown.

[0020] Figure 10 The processing flow of a station used for space reuse is shown.

[0021] Figure 11 The processing flow of a coordination device for space reuse is shown.

[0022] Figure 12 A schematic diagram of a machine in the form of a computing device is shown, wherein a set of instructions can be executed to cause the machine to perform one or more of the methods discussed herein.

[0023] Figure 13 An example of a simulation setup is shown, where each Basic Service Unit (BSS) covers all three rooms, and for example, a station (STA) can connect to two access points (APs) in each room.

[0024] Figure 14 This illustrates simultaneous transmission without coordination, where both APs transmit at full power simultaneously (there is no difference between the primary and secondary APs).

[0025] Figure 15 The C-SR transmission is illustrated, where the permissible transmit (TX) power selected for the secondary C-SR transmission is such that the interference and RX noise intensities are equal. AP1 acts as the primary AP for 50% of the transmission time, while AP2 acts as the primary AP for the other 50% of the transmission time.

[0026] Figure 16 The C-SR transmission is illustrated, where the allowable TX power selected for the secondary C-SR transmission allows the interference power at the STA to be 5 dB higher than the RX noise. AP1 acts as the primary AP for 50% of the transmission time, while AP2 acts as the primary AP for the other 50% of the transmission time.

[0027] Figure 17An example of zero-dropout transmission is shown, where the permissible interference for the secondary transmission is equal to the receiver noise. Zero-dropout techniques can be used to reduce interference to this level. Detailed Implementation

[0028] In dense WLAN environments where multiple networks use the same channel and their coverage overlaps, inter-network interference can be a major cause of performance degradation, leading to increased latency and reduced data rates.

[0029] Figure 1 The diagram illustrates two overlapping networks 100 consisting of two WLANs. Each network includes access points (APs) 110, 150 and one or more stations (STAs) 120, 130, 140, each equipped with multiple antennas. Typically, each AP or STA that may transmit data can perform a clear channel assessment (CCA) mechanism to avoid collisions caused by simultaneous transmissions.

[0030] Basic Service Units (BSSs) can be independent of each other, or a BSS can be part of an Extended Service Unit (ESS), which allows a STA to move from one BSS to another and provides additional coordination capabilities. Listen-before-talk protocols or request-to-send (RTS) / clear-to-send (CTS) protocols can reduce collisions, but may also limit the efficient use of spectrum and transmission time.

[0031] Coordinated Spatial Multiplexing (C-SR) is a method that allows simultaneous transmission under specific conditions, improving throughput and reducing latency.

[0032] Coordinated spatial multiplexing can be used to control interference between simultaneous transmissions to avoid packet loss. In spatial multiplexing scenarios, such as when two or more WLAN transmitters are transmitting simultaneously on the same frequency band, interference can be controlled by one or more of the following methods: (i) adjusting transmit power, (ii) enhancing robustness (e.g., by adjusting modulation schemes and / or forward error correction (FEC) overhead), or (iii) multiple-input multiple-output (MIMO) beamforming / precoding.

[0033] For each of these methods, interference information from the transmitter can be collected as perceived by the receiver.

[0034] For independent overlapping BSSs (OBSSs), allocation between stations and access points can be provided. In some examples, the primary transmission may not be aware of spatial multiplexing (simultaneous secondary transmissions), where interference from secondary transmissions should be minimized.

[0035] One consideration is the allocation of transmit power (e.g., for secondary transmissions). The determination of transmit power can be based on information about permissible interference at the STA receiver, which can be provided by the STA.

[0036] The transmit power allocation of the AP performing C-SR transmission can be determined by one or more of the following methods: (i) the first AP can acquire the channel and transmit at full power, (ii) the second AP can determine whether C-SR is feasible, and if so, determine the correct TX power and / or precoding / beamforming matrix to reduce the interference to the main transmission below an acceptable level. These operations can be used for two independent networks.

[0037] Alternatively or additionally, when using transmit precoding / beamforming matrices to reduce interference (e.g., spatial nulls), the goal is not to completely eliminate interference between APs, but to reduce the interference to below an acceptable level.

[0038] In a coordinated network (such as an Extended Service Unit (ESS)), additional optimization steps, namely AP-STA allocation, can be performed. This allocation can be performed in one or more of the following ways: (i) the master AP or central coordinating device initiates joint channel estimation, (ii) based on the knowledge of known channel conditions, the STA is allocated to one of the APs for service, (iii) the transmit power and / or precoding / beamforming matrix for transmissions to both APs is determined to achieve the overall maximum throughput, or (iv) the additional interference caused by spatial multiplexing is evaluated and considered to select the modulation scheme and FEC (forward error correction) overhead (MCS).

[0039] When using spatial nulling, there may be a trade-off between residual interference levels and precoder conditions. Precoder / beamforming matrices can tolerate some interference, achieving a balance between interference and signal levels.

[0040] In some examples, WLAN (Wi-Fi) ® Version 5 and earlier may perform free channel assessment (CCA) without using spatial multiplexing.

[0041] Wi-Fi ® 6 allows C-SR, but lacks channel feedback from the affected station. Therefore, interference from simultaneous transmissions may not lead to unexpected packet loss.

[0042] Full spatial nulling for coordinating multi-AP transmission has two drawbacks. First, the sum of the spatial flows of all simultaneously serving STAs must be less than or equal to the number of antennas of the AP with the fewest antennas, which limits the availability of spatial nulls. Second, the power loss on the transmit precoder due to spatial nulling can be high, especially when the actual interference path is weak and the additional interference without nulling is not too high.

[0043] This disclosure presents a method for measuring signal and interference power. A protocol for exchanging measurement results is proposed. A power allocation scheme for spatial multiplexing is defined.

[0044] In one example, C-SR can be used for independent Overlapping BSS (OBSS). In this case, each STA can listen for probe packets (non-data packets, NDP) from associated APs and other APs within its coverage area. For associated APs, regular probe feedback can be sent back to that AP. For unassociated APs, C-SR feedback packets can be provided, such as reporting actual interference and power backoff required for simultaneous transmission.

[0045] In one example, the feedback to the unassociated AP includes compressed channel feedback for the channel from that unassociated AP to the STA, used to perform spatial nulling. When the STA is being served, the AP that decides to perform C-SR transmission must keep the interference level of the corresponding STA below the requested level, for example, by reducing transmit power or employing spatial nulling.

[0046] In another example, C-SR can be used in an ESS, and the APs can coordinate their transmissions to a central coordinating device that performs coordination tasks for multiple APs. In this case, joint probes can be performed.

[0047] One of the APs (the primary AP) or a coordinating device can trigger NDP transmissions from one or more secondary APs and the primary AP according to a given start time and sequence. The sequence length should allow the channel between all AP transmit antennas and the receiver antenna of the probed STA to be estimated. The STA can send probe feedback to its associated AP.

[0048] Based on this feedback, the shared AP can perform one or more of the following operations: (i) select the optimized AP-STA association, (ii) trigger transmissions from all APs to the selected STA, (iii) adjust the transmit power in low interference conditions, (iv) employ spatial null techniques in high interference conditions, and (v) select the modulation and coding scheme and the number of spatial streams accordingly based on the interference / residual interference level obtained from the detection.

[0049] In some embodiments, the AP employs implicit channel estimation to support decision-making. Thus, channel attenuation between the STA and the access point can be calculated by receiving packets from these STAs and measuring the received power and received signal covariance. In cases where the STA does not provide channel estimation feedback, spatial nulling can be performed using the received signal covariance.

[0050] In some embodiments, in addition to NDP, the long training field (LTF) of the data packet can be evaluated to improve channel measurement and track channel changes (e.g., for mobile STAs).

[0051] Because transmissions from adjacent BSSs do not continuously block the channel, the proposed method reduces channel congestion, thereby increasing capacity and achieving lower latency. During C-SR, the probability of packet loss is minimized, and the secondary AP has explicit decision rules regarding tolerable interference during simultaneous transmissions.

[0052] Spatial nulling, aimed at achieving complete interference elimination—the proposed method of reducing interference to an acceptable level through spatial nulling may offer performance advantages to interference stations implementing nulling (due to better conditions for matrix inversion). Furthermore, partial nulling may be more robust to channel variations caused by movement or other conditions.

[0053] In one embodiment, the C-SR is applied to a separate Overlapping BSS (OBSS). AP-STA association can be provided via a service set identifier (SSID). This allows for contention-based channel access, where one AP wins the contention and thus gains primary access to the channel (primary AP).

[0054] To perform beamforming or multi-user multiple-input multiple-output (MU-MIMO) transmissions to associated STAs, the primary AP can send probe packets to the associated STAs. The secondary AP can also send probe packets to the associated STAs. Probe packet transmission can be based on a periodic pattern.

[0055] When a STA receives an NDP from an associated AP, the STA can probe for a response packet. When a STA receives an NDP from an unassociated AP, the STA can respond with a C-SR response packet, which may be a smaller packet and may not contain a complete MIMO feedback report.

[0056] like Figure 2As shown in the timing diagram 200, the secondary AP 260 can first provide a Null Data Packet (NDP) advertisement 202, followed by a delay 204, and then send the NDP 206. When associated with an AP, STA 1 270 and STA N 280 can send probe feedback 212 and 214. When not associated with an AP, STA 1 270 and STA N 280 can send C-SR feedback 216 and 218.

[0057] The primary AP 210 can first provide an NDP advertisement 222, followed by an NDP 226 after a delay of 224. STA 1 270 and STA N 280 can send probe feedback 232 and 234 to the primary AP 210. STA 1 270 and STA N 280 can send C-SR feedback 236 and 238 to the primary AP. The primary AP 210 can send data packet 242. The secondary AP 260 can send C-SR data packet 244.

[0058] WLAN transmission uses data from the AP. s of Root transmitting antenna, in K carrier Orthogonal Frequency Division Multiplexing (OFDM) transmission is performed on the STA. Each STA All are equipped with Root receiving antenna.

[0059] Transmission can be achieved through multiple spatial streams Composition, in which each STA receives A spatial flow, making The total number of receiving antennas in MU MIMO transmission is .

[0060] For precoded or beamforming transmissions, the MIMO transmitter (AP) will precode the matrix... Applied to the input signal vector Thus, the transmitted signal vector is obtained.

[0061] in After the signal is transmitted through the channel, the received signal is...

[0062] Each STA receiver uses a receiver equalizer. Perform receive equalization to restore the transmitted signal. Its expression is

[0063] For MIMO channel estimation, and during receiver initialization on regular data packets, LTF symbols with orthogonal sequences are transmitted in the symbol preamble for use in MIMO channel measurements.

[0064] The sequence length is A symbol. At time At that location, transmit the transmitted signal vector .

[0065] These signals form an orthogonal sequence, such that The conditions are met. Given the transmission sequence, the receiver can perform channel estimation using the following formula.

[0066] Therefore, the source of the received signal could be either the serving AP or the interfering AP. The receiver noise covariance can also be estimated by repeating orthogonal sequences or by averaging adjacent carriers. .

[0067] , .

[0068] Therefore, statistical independence between the desired signal and interference can be provided. Noise covariance estimation can be used, for example, to estimate interference during the reception of LTF symbols from desired data or NDP transmissions.

[0069] Based on the above measurement results, the STA can assess the interference generated by APs operating in the same frequency band within the coverage area.

[0070] In one embodiment, such as Figure 2 As shown, the interference power from the interfering AP can be measured during the NDP transmission period of the interfering AP. The interfering AP at time... t The transmitted (pre-coded) TX signal vector is denoted as .

[0071] For carrier k The interference covariance experienced by the receiving STA is

[0072]

[0073] Furthermore, antenna n and carrier k The interference above is .

[0074] From interfering AP d To STA s The average interference is:

[0075] The STA has an inherent noise level σ 2 This makes the total noise + interference level STA will assume a maximum noise increment, for example Therefore,

[0076] For example, when At that time . AP power backoff (Relative to NDP's transmit power) is

[0077] The value is restricted to be less than 1.

[0078] This power can be backed up and transmitted to the interfering AP. For the interfering AP, in order to serve the STA... s Simultaneous transmission is performed at the same time, and its tx power is

[0079] The standard transmission power is For example, the transmit power used for NDP transmission.

[0080] In another example, interference can be measured during the reception of the LTF sent by the serving AP. Noise covariance measurement. It may be available. However, in the presence of more than one interfering transmission, it cannot be assigned to a specific interfering source d.

[0081] The diagonal elements of the noise covariance matrix are the sum of noise and interference. For example,

[0082] Therefore, the power back-off of the interfering AP

[0083] In another example, the interfering AP and the serving AP can perform joint detection using orthogonal sequences of length T (see [link to example]). Figure 6 This enables channel estimation for both direct and interfering channels.

[0084] The channel is now estimated as follows:

[0085] The interference covariance is

[0086] The transmit covariance of the jamming AP is known. ,For example Once the interference covariance is known, the power backoff is calculated in the same way as the interference measurement performed separately for NDP transmissions from interfering APs.

[0087] In one example, averaging is performed on carriers k=1,…,K. In another example, averaging is performed on a set of carriers, such as a fixed number N. g Each carrier or resource unit (RU) carrier. Accordingly, power back-off is transmitted to the interfering AP as the average of all carriers, the average of each group of carriers, or the average of each RU.

[0088] Although the additional interference from C-SR can be kept at a low level, the receiver noise + interference to the primary receiver will always increase due to the presence of the secondary transmission. This noise + interference increment... It has a significant impact on determining the modulation and coding scheme and transmission settings.

[0089] In one embodiment, AP definition The value is then passed to STA.

[0090] In another example, determined by STA The data is then transmitted to the AP to select transmission settings. Communication varies depending on the method the AP uses to determine the transmission settings (modulation coding scheme and number of spatial streams).

[0091] In one example, with The corresponding noise margin value is transmitted to the AP via a dedicated message.

[0092] In another example, the AP determines transmission settings based on the signal-to-noise ratio (SNR) feedback in the probe feedback response. The STA reduces the measured SNR when sending the probe feedback response. In this way, the transmission settings selected by the AP will allow sufficient margin for interference generated by secondary transmissions.

[0093] In another example, the AP uses a trial-and-error approach to determine the transmission settings. When the STA receives packets during a secondary transmission, or when the transmission settings provide sufficient noise immunity, no action may be necessary. However, when the STA receives packets without a secondary transmission, and the transmission settings prevent reception of these packets in the presence of interference, the STA can artificially increase the noise level. Alternatively, it may return a negative acknowledgment for such packets. Subsequently, the AP's link adaptation mechanism will adjust accordingly to maintain stable transmission settings even under interference caused by secondary transmissions.

[0094] When a probe NDP is received from the serving AP, the compressed channel feedback sent to the serving AP consists of two sets of data: the compressed channel matrix (i.e., the singular value decomposition of the estimated channel matrix). (The normalized V matrix). Furthermore, according to singular values... S The calculated expected SNR will be based on the antenna. SNR n Or by antenna and carrier group Reporting is then performed. The compressed V matrix is ​​equivalent to the effective channel, such as the channel and receiver equalizer. .

[0095] Typically, the C-SR feedback packet includes an ID so that the receiving AP (interference AP) can identify the STA.

[0096] In one example, the C-SR feedback group includes power backoff values. This value will be applied simultaneously with the transmission of the corresponding STA service by the interfering AP for sending C-SR feedback. This can be a single value, i.e., the average of all carriers. In another example, the feedback report includes values ​​related to multiple carriers or carrier groups. .

[0097] In addition, interference power It can be a single average value over all carriers. It can be provided separately by carrier group or by RU.

[0098] To achieve interference null, the STA provides an effective interference channel. .

[0099] The compressed V matrix for conventional detection feedback is represented using a proportional representation. The scaling vector is selected. To reduce the quantization error of the feedback.

[0100] In another example, C-SR feedback is measured via joint detection (see [link to example]). Figure 6 In this case, STA has measured... and ,and This is related to the interfering AP, so it needs to be transmitted in the C-SR feedback report.

[0101] A compressed form (e.g., amplitude / phase format or) In SVD U and V H (normalized form of the matrix), along with singular values ​​s and the maximum permissible disturbance level These together constitute the components of the C-SR feedback report.

[0102] Based on this, the interfering AP can decide to reduce its transmission power and simultaneously transmit to the transmission service STA. m Furthermore, interference can be reduced by selecting transmit precoding for the interfering AP (spatial null).

[0103] A secondary AP may initiate a C-SR transmission overlapping with the primary transmission when the following conditions are met: (1) a preamble of the primary transmission has been received; (2) the STA is served by the primary transmission and (a) a C-SR feedback packet has been received, or (b) the STA is within the coverage area of ​​the secondary transmission (e.g., no NDP feedback sent by the STA to the primary AP has been detected), or (c) a spatial null can be formed for the STA to reduce interference below a threshold; and (3) the channel quality implemented by the secondary transmission is high enough to ensure successful packet reception. This threshold depends on the modulation and coding settings. The transmit power of the C-SR transmission can be defined by the following equation (11).

[0104] In one example, the channel quality of the secondary transmission is evaluated through trial and error. For example, packets are first sent with low-order modulation and coding schemes. If the reception is successful, the MCS can be improved in subsequent transmissions.

[0105] In another example, the interference level of the main AP. This can be obtained from the C-SR feedback packets already sent by the served STA. The expected signal-to-noise ratio (SINR) is then given by the following formula.

[0106] The AP can use this information to determine whether to perform C-SR transmission.

[0107] Even when the interference level does not meet the requirements for simultaneous transmission, transmission can still be achieved through nulls. Therefore, transmit precoding for the secondary transmission is selected to reduce the interference at the victim STA to below the expected level. Interference channel estimation feedback (e.g., effective interference channel) is also included. Used to execute zero traps.

[0108] The primary or secondary AP that has not performed zero forcing calculates the (zero forcing) precoding matrix according to the following formula.

[0109] in

[0110] scaling factor The choice of [aspect] must satisfy power constraints. This is an example. Other methods can also be used, such as block diagonalization or MMSE (minimum mean square error).

[0111] For the secondary AP, it serves the STA. d =1,…, D And it creates a spatial null trap for STA m, whose effective channel is

[0112] Achieve complete zero-depression through the following methods

[0113] Invert the complete matrix and select the service station. d =1,…, D Submatrix:

[0114] Based on the matrix conditions, scaling required to meet power constraints reduces performance compared to precoding without zero traps.

[0115] In most cases, a complete null trap, as given in Equation (20), might impose a large penalty to adjust the precoding matrix. In practice, a complete null trap is not necessary; it is sufficient to reduce the interference to below an acceptable level, which allows for some SNR loss. For this purpose, an interference scaling parameter is introduced. λ ,in λ m =0 represents a complete zero trap, while This indicates a full interference scenario.

[0116] To introduce scaling, equation (19) is changed to

[0117] in , while equation (20) remains unchanged.

[0118] Equation (21) represents a partial zero-trap implementation of zero-forcing precoding. For MMSE or BD precoding, interference control parameters are introduced in a similar manner. λ In the example of C-SR in a standalone network, the performance improvement achieved through zero traps is limited because the primary AP transmits without being aware of the secondary AP's transmissions, for example, without performing zero traps to reduce interference with the secondary AP's transmissions.

[0119] like Figure 3 The example shown illustrates the control of null interference relationships. In this example, the interference SNR may be improved compared to a completely null situation, while the permissible SNR of the affected party may decrease. The decrease in the affected party's SNR may occur simultaneously with the increase in interference experienced by the affected party.

[0120] This avoids setting unreasonably low tolerance levels in C-SR feedback packets. STAs can gain some benefit by allowing interference. For example, APs can define some tolerance increments for STAs (this is practically meaningful because APs can determine the modulation and coding scheme (MCS) and reserve some interference margin).

[0121] When an access point (AP) allows more space to be reused, it will receive a higher channel access priority in return. Since the AP will not completely block the channel, it is acceptable for the AP to acquire the channel more frequently.

[0122] In some examples, multiple access points can form an Extended Service Unit (ESS), allowing for more advanced coordination between access points. Within a managed network, a coordinating device assigns stations to access points and allocates resources for concurrent transmissions.

[0123] In such Figure 4 In one example of the two overlapping networks 400 shown, the coordinating device 460 can be a standalone device in the network, connected to all access points via a wired or wireless backhaul connection. In this example, AP 410 can be part of BSS 1, and AP 450 can be part of BSS 2. STAs 420, 430, and 440 can be part of the network. The coordinating device 460 can coordinate between AP 410 and AP 450.

[0124] In another example, such as Figure 5 In the two overlapping networks 500 shown, coordination is handled by one of the access points. The AP performing inter-ESS coordination can vary depending on the packet. Coordinating device 460 can be integrated with AP 410. In this example, AP 510 can be part of BSS 1, while AP 550 can be part of BSS 2. STAs 520, 530, and 540 can be part of this network. Coordinating device 560 can coordinate between AP 510 and AP 550.

[0125] In one example, precoder coefficient calculation can be performed in the coordinating device and transmitted to other APs for joint transmission. In another example, joint power allocation can be performed in the coordinating device, and each AP can locally calculate precoder or beamforming coefficients.

[0126] For coordinated transport in a managed network, methods such as Figure 6 The joint detection method is shown in timing diagram 600. The coordinated transmission is initiated by one of the APs or by the coordinating device.

[0127] AP1 610 can send a multi-AP NDP trigger 602, followed by a delay of 604, and then send an empty data packet 606. AP2 660 can send an empty data packet 608. STA 1 670 and STA 2 680 can send probe feedback 612 and 614 to AP1 610. STA 1 670 and STA 2 680 can send probe feedback 616 and 618 to AP2 660. AP1 610 can send a multi-AP trigger 622, followed by a data packet 624. AP2 660 can send a C-SR data packet 626, followed by a multi-AP data trigger 628 and a data packet 634. AP1 610 can send a C-SR data packet 632.

[0128] In a managed multi-AP network, additional degrees of freedom can be used for optimization. For example, STAs can be migrated to other APs to improve overall performance, and the main transmission can be performed under higher interference conditions to increase total throughput.

[0129] Fairness is not guaranteed by fixed rules in the standard, but by a central management entity, which can be part of one of the APs or located elsewhere in the network.

[0130] In a managed network, we can make the primary AP aware of the transmissions and interference from the secondary APs. The primary AP can then reduce its MCS accordingly. The secondary AP can then transmit at higher power to achieve joint optimization. In most cases, when the primary user is protected, the combined rate for joint optimization between the primary and secondary users is higher than the achieved rate. Figure 7 An example is shown. While it is possible to search for optimal power allocation, in most cases, such as... Figure 7 In the rate region shown, with the gain provided by C-SR, a full search is not required because a joint optimal rate can be achieved when both APs transmit at full power.

[0131] In one example, power allocation optimization is performed by the AP that triggers C-SR transmission. Power levels are transmitted during multi-AP data triggering. In another example, a separate entity may exist within the network that can perform resource allocation for multiple connected APs.

[0132] Each transmitting AP can determine whether to actually use the transmission opportunity and the MCS to be adopted based on the interference level information provided by the optimization.

[0133] In a coordinated network, a STA can be served by multiple APs within its coverage area. In most cases, the nearest AP (e.g., the AP with the least AP-STA attenuation) provides the optimal allocation. However, especially when the attenuation differences between APs are small, the remaining capacity of the APs can be considered. Rate-optimized AP-STA association can be performed using an iterative approach, where each STA is reassigned to the AP that provides the highest total data rate. For a single STA, all possible options (e.g., all APs within coverage area) can be tested, and the total rate can be evaluated.

[0134] In a standalone network scenario, the secondary AP performs zeroing; the primary AP interferes with them completely, while managed networks can use mutual zeroing by default. Both the primary and secondary APs can perform zeroing whenever the overall speed is increased.

[0135] Implementing nulls in a primary AP requires resources; for example, the sum of the number of spatial nulls and the transmit spatial flow must not exceed the number of TX antennas for that AP. Therefore, nulls can only be applied when resources are available or when the gain of the secondary AP is higher than the loss of the primary AP after resource reallocation.

[0136] Reducing latency may be another objective, for example, by using C-SR and zero-traps techniques to serve more STAs simultaneously, thereby reducing the overall latency compared to the overall latency of time-division multiplexing.

[0137] In one example, the precoding coefficients used for zero traps are jointly computed, for example by the coordinating device or by one of the APs. This allows for joint optimization of the individual precoders of the APs, for example through iterative optimization.

[0138] Multiple APs (e.g.) and The independent precoder matrices constitute the joint precoder matrix.

[0139] The coefficients that are not associated with any AP are zero.

[0140] Similarly, the joint equalizer matrix

[0141] It consists of equalizer matrices for each STA.

[0142] The equalizer for STA m is given by the following formula:

[0143] in , Including with STA m Columns of the associated precoder matrix, for example ,and Including with STA m The row associated with the receiving antenna, for example .

[0144] Noise + Crosstalk Covariance Matrix Given by the following formula

[0145] The precoder is calculated based on the full-duplex uplink channel in the full-duplex uplink.

[0146] APs' duplex uplink equalizer Given by the following formula

[0147] in .

[0148] This indicates uplink power optimization, expressed by the formula... Convert it from an uplink to a downlink. Let represent the Lagrangian variable of the total power constraint for each AP. It is updated according to the following formula: .

[0149] By iteratively updating the precoder and equalizer multiple times, the optimal zero-trap precoder for AP can be found.

[0150] STA receivers for C-SRs can suppress interference. Since interference from other APs is spatially dependent noise, interference suppression on the receiver side can be very effective, especially when the number of RX antennas on the STA exceeds the number of spatial flows to the receiver. Each additional receive antenna eliminates one source of interference.

[0151] Therefore, the received covariance is estimated and incorporated into the equalizer calculation, for example, by calculating the equalizer using the following formula. .

[0152] Typically, C-SR is symmetrical. For uplink transmissions, the AP provides the receiver with information about acceptable interference levels.

[0153] The key difference is that uplink transmission can be performed without the STA sending probe packets. Therefore, the AP can rely on implicit measurements to identify interference.

[0154] The AP can send C-SR packets to the STA or other APs, enabling them to send simultaneously while receiving uplink transmissions.

[0155] In another example, sign alignment is used for efficient precoding. Start-time alignment can be used; otherwise, the (non-precoded) preamble (before the Ultra High Throughput Long Training Field (EHT-LTF)) could cause crosstalk from the secondary AP into the primary AP transmission. To avoid interference, C-SN transmission can be triggered simultaneously by the primary AP (suitable for both semi-coordinated and fully coordinated scenarios).

[0156] In another example, to simplify C-SN operation, the trigger frame may include information such as the servicing STA and the permissible interference for each STA (e.g., when the selected MCS results in a higher level of interference than indicated by the STA feedback).

[0157] In another example, the STA allows the C-SN to withstand a certain noise + interference increment (e.g., 3dB). For the AP... d The feedback included: to make AP d For STA v Power backoff required to keep interference below desired limits And zero-traps space feedback. When AP d Launch and STA v During reception, the transmission power is reduced to If a significant reduction is required, a null space can be used to maintain a high transmit power. At the same time, reduce interference, among which λ Control the depth of the zero trap.

[0158] In another example, the zero-trapped space feedback can be determined.

[0159] The detection feedback can be determined by the following formula: Channel estimation Singular value decomposition With an already equalized channel Corresponding feedback use .

[0160] C-SN feedback can be determined by the following formula: channel estimation from the uncorrelated AP NDP. Singular value decomposition Furthermore, this C-SR corresponds to the interference source channel at the equalizer output. Feedback was received .

[0161] In another example, multi-AP probing can be performed jointly to improve efficiency. Different APs operate as single APs and collaboratively send LTFs (each AP uses a different spatial mapping on the LTF). For joint precoder optimization, probing feedback is collected at a central coordinating node (e.g., AP1) to compute the precoder. The precoder can then be distributed to other APs via precoder messages.

[0162] In another example, optimal partial nulling of the C-SN can be used. C-SR with only power backoff (no nulling) and C-SN with complete nulling represent two extreme cases. Interference can be reduced by lowering transmit power, using spatial nulling, or a combination of both. Complete nulling (zero-forcing) often leads to ill-conditioned precoder matrices. To avoid this, null depth can be used. λ Partial zeroing. Complete zeroing may be worse than no zeroing at all.

[0163] In another example, the overhead can be determined. The overhead can include various assumptions, such as: the baseline is MU-MIMO Time Division Multiple Access (TDMA); the transmission opportunity (TXOP) duration is 6 milliseconds; the expected probe interval is approximately 10 ms (or 2 TXOPs); all management frames are transmitted at the full bandwidth of MCS 0; and the C-SN feedback for each carrier group is 2 bytes.

[0164] In this case, the approximate overhead might be: (1) MU-MIMO detection (2 OBSS): the detection overhead is about 7% of the air interface time; (2) MU-MIMO detection + C-SN feedback: the overhead increases from 7% to 10% (for C-SN feedback); (3) joint detection: the overhead decreases from 7% to 6%.

[0165] In another example, partial nulls can be compared to complete nulls. For probe feedback, the effective channel can be fed back via the V matrix for data transmission. Characterization. For C-SN feedback, null feedback exists for the space null. For a complete zero-depression, and For some zero-depression, and For associated STAs ,use ,in diagonal elements are A diagonal matrix.

[0166] In another example, null trap accuracy can depend on a number of influencing factors. Zero-forcing (ZF) null traps may not achieve ideal results in practice due to reasons including: (i) channel estimation accuracy (feedback format, packetization, and interpolation), (ii) channel aging, and (iii) inter-AP clock differences.

[0167] In another example, spatial nulling and symbol alignment can be performed. For OFDM symbol boundaries, spatial nulling is not complete. Interference at symbol boundaries depends on channel characteristics (e.g., a flat channel will not cause interference at symbol boundaries). Interference depends on transmit signal characteristics, such as the tx window. If OFDM symbol boundaries are aligned, this interference will not affect the receiver.

[0168] In another example, alignment may include several requirements. For timing and clock synchronization, the synchronization requirements are much lower than those for joint transmissions, where the allowable drift in sampling timing is only a portion of the sampling period. Depending on channel conditions, an offset of several sampling periods is acceptable. A clock accuracy of + / - 0.07 ppm is sufficient to maintain this range.

[0169] Figure 8 A block diagram of an example communication system 800 configured for spatial multiplexing according to at least one example described in this disclosure is shown. The communication system 800 may include a digital transmitter 802, radio frequency circuitry 804, a device 814, a digital receiver 806, and a processing device 808. The digital transmitter 802 and the processing device are configured to receive baseband signals via a connection 810. A transceiver 816 may include the digital transmitter 802 and the radio frequency circuitry 804.

[0170] In some examples, communication system 800 may include a system of devices configured to communicate with each other via wired or cable connections. For example, wired connections in communication system 800 may include one or more Ethernet cables, one or more fiber optic cables, and / or other similar wired communication media. Alternatively or additionally, communication system 800 may include a system of devices configured to communicate via one or more wireless connections. For example, communication system 800 may include one or more devices configured to transmit and / or receive radio waves, microwaves, ultrasound, light waves, electromagnetic induction, and / or similar wireless communications. Alternatively or additionally, communication system 800 may include a combination of wireless and / or wired connections. In these and other examples, communication system 800 may include one or more devices configured to acquire a baseband signal, perform one or more operations on the baseband signal to generate a modified baseband signal, and transmit the modified baseband signal (e.g., to one or more loads). In some examples, communication system 800 may include one or more communication channels that can communicatively couple systems and / or devices included within communication system 800. For example, transceiver 816 may be communicatively coupled to device 814. In some examples, transceiver 816 may be configured to acquire a baseband signal. For example, as described herein, transceiver 816 may be configured to generate a baseband signal and / or receive a baseband signal from another device. In some examples, transceiver 816 may be configured to transmit a baseband signal. For example, after acquiring a baseband signal, transceiver 816 may be configured to transmit the baseband signal to a separate device (such as device 814). Alternatively or additionally, transceiver 816 may also be configured to modify, condition, and / or convert the baseband signal before transmitting it. For example, transceiver 816 may include a quadrature upconverter and / or a digital-to-analog converter (DAC), which may be configured to modify the baseband signal. Alternatively or additionally, transceiver 816 may include a direct radio frequency (RF) sampling converter, which may be configured to modify the baseband signal.

[0171] In some examples, digital transmitter 802 may be configured to acquire a baseband signal via connection 810. In some examples, digital transmitter 802 may be configured to up-convert the baseband signal. For example, digital transmitter 802 may include a quadrature up-converter for processing the baseband signal. In some examples, digital transmitter 802 may include an integrated digital-to-analog converter (DAC). This DAC can convert the baseband signal into an analog signal or a continuous-time signal. In some examples, the DAC architecture may include a direct RF sampling DAC. In some examples, the DAC may be a component separate from digital transmitter 802.

[0172] In some examples, transceiver 816 may include one or more sub-components that can be used for baseband signal preparation and / or baseband signal transmission. For example, transceiver 816 may include an RF front-end (e.g., in a wireless environment) that may include a power amplifier (PA), a digital transmitter (e.g., 802), a digital front-end, an IEEE 1588v2 device, a Long Term Evolution (LTE) physical layer (L-PHY), an (S-plane) device, a management plane (M-plane) device, an Ethernet Media Access Control (MAC) / Personal Communication Services (PCS) device, a resource controller / scheduler, and other components. In some examples, the radio of transceiver 816 (e.g., RF circuitry 804) may be synchronized with the resource controller via the S-plane device, which may contribute to high-precision timing relative to a reference clock.

[0173] In some examples, transceiver 816 may be configured to acquire a baseband signal to be transmitted. For example, transceiver 816 may receive a baseband signal from a separate device, such as a signal generator. For example, the baseband signal may originate from the audio signal output of a transducer configured to convert variables into electrical signals, such as a microphone picking up a speaker's voice. Alternatively or additionally, transceiver 816 may also be configured to generate a baseband signal to be transmitted. In these and other examples, transceiver 816 may be configured to transmit a baseband signal to another device, such as device 814.

[0174] In some examples, device 814 may be configured to receive transmissions from transceiver 816. For example, transceiver 816 may be configured to transmit baseband signals to device 814. In some examples, the radio frequency circuit 804 may be configured to transmit digital signals received from the digital transmitter 802. In some examples, the radio frequency circuit 804 may be configured to transmit digital signals to the device 814 and / or the digital receiver 806. In some examples, the digital receiver 806 may be configured to receive digital signals from the RF circuit and / or transmit digital signals to the processing device 808. In some examples, processing device 808 may be a standalone device or system as shown in the figures. Alternatively or additionally, processing device 808 may also be a component of another device and / or system. For example, in some examples, processing device 808 may be included in transceiver 816. When processing device 808 is a standalone device or system, it may be configured to communicate with additional devices and / or systems (e.g., transceiver 816 and / or device 814) located remotely relative to processing device 808. For example, processing device 808 may be configured to send transmissions to and / or receive transmissions from transceiver 816 and / or device 814. In some examples, processing device 808 may be combined with other elements of communication system 800.

[0175] Figure 9 A flowchart of a space reuse example method 900 according to at least one example described in this disclosure is shown. The method 900 can be configured according to at least one example described in this disclosure.

[0176] Method 900 can be executed by processing logic, which may include hardware (circuit, special-purpose logic, etc.), software (such as software running on a computer system or special machine), or a combination of both. Such processing logic may be included in... Figure 12 Processing device 1202, Figure 8 The communication system 800 or other device, device combination or system.

[0177] The method 900 may begin at block 905, where the processing logic may receive information about the interference path between the STA and the AP.

[0178] At box 910, the processing logic can select the transmit power based on information about the interference path between the STA and the AP.

[0179] At box 915, the processing logic can determine the transmission type based on the transmit power.

[0180] At box 920, the processing logic can transmit based on this transmission type.

[0181] Information about the interference path between the STA and the AP may include one or more of the following: the transmit power backoff required for simultaneous transmission, or the AP's maximum permissible transmit power.

[0182] Information about the interference path between the STA and AP may include information for spatial nulls.

[0183] The method may further include: at the AP, receiving additional information about another interference path between the other STA and the AP from another station (STA); at the AP, setting the transmit power to a minimum transmit power based on the following information: information about the interference path between the STA and the AP, and additional information about the other interference path between the other STA and the AP.

[0184] The method may further include: calculating a minimum transmit power based on a preamble received from one or more of the STA or the other STA; or calculating the minimum transmit power based on the minimum transmit power of the STA and the other STA.

[0185] The method may further include: at the AP, calculating the expected signal quality for spatial multiplexing transmission, wherein the transceiver may transmit the spatial multiplexing transmission when the expected signal quality of the spatial multiplexing transmission is greater than a threshold.

[0186] The method may further include: at the AP, when the transmission power required by the STA falls back to a threshold, determining the transmission type as spatial null transmission.

[0187] The method may further include: calculating a noise and interference threshold at the AP; and sending the noise and interference threshold from the AP to the STA.

[0188] The method may also include: at the AP, selecting one or more of the following: modulation coding scheme or several spatial streams.

[0189] Method 900 may be modified, added to, or removed without departing from the scope of this disclosure. For example, in some examples, method 900 may include any number of other components not explicitly illustrated or described.

[0190] Figure 10 A flow diagram of an example method 1000 for spatial reuse, according to at least one example described in this disclosure, is shown. The method 1000 can be configured according to at least one example described in this disclosure.

[0191] Method 1000 can be executed by processing logic, which may include hardware (circuit, special-purpose logic, etc.), software (such as software running on a computer system or special machine), or a combination of both. Such processing logic may be included in... Figure 12 Processing device 1202, Figure 8 The communication system 800 or other device, device combination or system.

[0192] Method 1000 may begin at box 1005, where the processing logic may receive probe packets.

[0193] At box 1010, the processing logic can compute Coordinated Space Reuse (C-SR) feedback.

[0194] At box 1015, the processing logic can send C-SR feedback to the AP.

[0195] C-SR feedback can be one or more of the following: power back-off required by the STA, effective channel estimation from the AP to the STA, or signal and interference noise levels.

[0196] The method may further include: at the STA, receiving the permissible interference and noise level from the AP; and at the STA, calculating the required power back-off based on the permissible interference and noise level.

[0197] The method may further include: at the STA, calculating the permissible interference and noise level, wherein the transceiver may transmit the permissible interference and noise level to the AP.

[0198] The method may also include simulating the increased noise interference level at the STA when the secondary transmission is not activated.

[0199] Method 1000 may be modified, added to, or omitted without departing from the scope of this disclosure. For example, in some examples, method 1000 may include any number of other components not explicitly illustrated or described.

[0200] Figure 11 A flow diagram of an example method 1100 for spatial reuse, according to at least one example described in this disclosure, is shown. The method 1100 can be configured according to at least one example described in this disclosure.

[0201] Method 1100 can be executed by processing logic, which may include hardware (circuit, special-purpose logic, etc.), software (such as software running on a computer system or special machine), or a combination of both. Such processing logic may be included in... Figure 12 Processing device 1202, Figure 8 The communication system 800 or other device, device combination or system.

[0202] Method 1100 may begin at box 1105, where the processing logic may send a joint probe process trigger to the first AP.

[0203] At box 1110, the processing logic can send the joint probe process trigger to the second AP.

[0204] At box 1115, the processing logic can receive the first probe feedback from the first AP.

[0205] At box 1120, the processing logic can receive a second probe feedback from the second AP.

[0206] At box 1125, the processing logic may determine one or more of the following: the transmit power of one or more of the first AP or the second AP, and the space null of one or more of the first AP or the second AP.

[0207] The coordination device can be integrated with either the first or second AP. Alternatively, the coordination device can be separated from both the first and second APs.

[0208] The method may further include: identifying one or more stations (STAs) to be simultaneously served; associating the one or more STAs with a first AP or a second AP; or calculating the transmit power of one or more of the first APs or the second APs.

[0209] The method may also include: at the coordinating device, calculating one or more beamforming coefficients of one or more of the first AP or the second AP.

[0210] The method may also include: at the coordination device, using one or more beamforming coefficients, calculating spatial nulls for one or more of the first AP or the second AP.

[0211] Method 1100 may be modified, added to, or removed without departing from the scope of this disclosure. For example, in some examples, method 1100 may include any number of other components that are not explicitly illustrated or described.

[0212] For ease of illustration, the methods and / or processes described herein are depicted and described as a series of actions. However, the actions involved in this disclosure may be performed in different orders and / or concurrently, and may be implemented in combination with other actions not presented and described herein. Furthermore, it is not necessary to use all illustrated actions to implement the methods according to the subject matter of this disclosure. In addition, those skilled in the art will understand and recognize that the methods may also be represented by a series of interrelated states through state diagrams or events. Furthermore, the methods disclosed in this specification can be stored on an article of art (e.g., a non-transitory computer-readable medium) to facilitate the transfer and assignment of these methods to a computing device. The term "article of art" as used herein is intended to encompass a computer program accessible from any computer-readable device or storage medium. Although illustrated as discrete modules, modules may be further divided into more modules, merged into fewer modules, or omitted depending on specific implementation requirements.

[0213] Figure 12 The schematic representation of a machine is illustrated using computing device 1200 as an example, which can execute a set of instructions to implement any or more of the methods described herein. Computing device 1200 may include a rack-mount server, router computer, server computer, mainframe computer, laptop computer, tablet computer, desktop computer, or any computing device having at least one processor, within which a set of instructions can be executed to enable the machine to implement any or more of the methods described herein. In an alternative example, the machine may establish a connection (e.g., network) with other machines via a LAN, intranet, extranet, or the Internet. The machine may operate as a server machine in a client-server network environment. Furthermore, although only a single machine is shown, the term "machine" should also include a collection of machines that individually or jointly execute a set (or more) of instructions to implement any or more of the methods described herein.

[0214] Example computing device 1200 includes processing device (e.g., processor) 1202, main memory 1204 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM), such as synchronous DRAM (SDRAM)), static memory 1206 (e.g., flash memory, static random access memory (SRAM)), and data storage device 1216, these components communicating with each other via bus 1208.

[0215] Processing device 1202 represents one or more general-purpose processing devices, such as microprocessors, central processing units, etc. More specifically, processing device 1202 may include complex instruction set computing (CISC) microprocessors, reduced instruction set computing (RISC) microprocessors, very long instruction word (VLIW) microprocessors, or processors implementing other instruction sets, or processors implementing combinations of instruction sets. Processing device 1202 may also include one or more special-purpose processing devices, such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), network processors, etc. Processing device 1202 is configured to execute instructions 1226 to perform the operations and steps discussed herein.

[0216] The computing device 1200 may also include a network interface device 1222, which can communicate with the network 1218. The computing device 1200 may also include a display device 1210 (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device 1212 (e.g., a keyboard), a cursor control device 1214 (e.g., a mouse), and a signal generation device 1220 (e.g., a speaker). In at least one example, the display device 1210, the alphanumeric input device 1212, and the cursor control device 1214 may be combined into a single component or device (e.g., an LCD touchscreen).

[0217] Data storage device 1216 may include computer-readable storage medium 1224 storing one or more sets of instructions 1226 that instantiate any or more methods or functions described herein. The instructions 1226 may also reside wholly or at least partially in main memory 1204 and / or processing device 1202, which also constitute computer-readable media, during execution by computing device 1200. The instructions may also be transmitted or received via network 1218 through network interface device 1222.

[0218] Although the computer-readable storage medium 1224 is shown as a single medium in the example, the term "computer-readable storage medium" can include a single medium or multiple media (e.g., a centralized or distributed database and / or associated cache and server) storing one or more sets of instructions. The term "computer-readable storage medium" can also include any medium capable of storing, encoding, or carrying a set of instructions that are executed by a machine and cause the machine to perform any one or more methods of this disclosure. Therefore, the term "computer-readable storage medium" can be understood to include, but is not limited to, solid-state memory, optical media, and magnetic media.

[0219] Example The following provides examples of performance characteristics based on the examples in this disclosure.

[0220] Example 1: The following results demonstrate the performance of the proposed method. Figure 13 As shown in the schematic diagram 1300, which includes three rooms (room 1, room 2, and room 3), two access points (APs) 1310 and 1360 simultaneously serve four STAs 1320, 1330, 1340, and 1350. The four STAs are positioned at different locations within the three rooms, maintaining a minimum distance of at least 2 meters from the APs, and are located on a 2m × 2m grid. The reference case illustrates the prior art.

[0221] For the OBSS scenario, the C-SR results must be compared with reference scheme 3, where the STA is associated with two different APs and time-division multiplexing is performed between the STAs.

[0222] Reference Cases: Reference Scheme 1 (BF): Beamforming and TDMA from one AP allocate 25% of the transmission time to each of the 4 STAs. Reference Scheme 2 (MU MIMO): MU MIMO transmission serves 4 STAs simultaneously through 1 AP. Reference Scheme 3 (MU-MIMO 2): MU MIMO transmission serves 2 STAs simultaneously, while TDMA is performed between APs.

[0223] Test case: Uncoordinated space reuse ( Figure 14 ); C-SR in OBSS that does not have zero-trap capability, different permissible interference levels ( Figure 15 , Figure 16 ); C-SR in OBSS with zero space trap ( Figure 17 ).

[0224] Example 2: Figure 14 This illustrates the rate-distance relationship in non-coordinated spatial multiplexing. Two APs transmit simultaneously to two STAs, each using full transmit power. The rate is high as long as all STAs are close to their associated APs. Otherwise, the rate will be lower than the data rate achieved through crosstalk avoidance. This situation is unstable because many STAs are not served at all.

[0225] Example 3: Figure 15 and Figure 16The rate-distance relationship for coordinated spatial multiplexing is illustrated. The primary AP transmits at full power. The secondary AP transmits at lower power as needed. Results show that the primary transmission is always successful, but the primary data rate may be reduced due to a potential 3dB drop in SNR. Although the rate appears lower, it should be noted that 20% (noise = interference) or 24% (noise + 5dB = interference) of STAs enjoy significantly reduced latency because they can transmit at any time without interference from other APs monopolizing the channel.

[0226] Example 4: Figure 17 The spatial null is shown. This provides the highest data rate for the secondary channel. Because interference is more likely, the penalty for the primary transmission is slightly higher. Furthermore, 38% of STAs enjoy ultra-low latency.

[0227] Several embodiments have been described. However, it should be understood that various modifications can be made without departing from the spirit and scope of this disclosure. Therefore, other embodiments are all within the protection scope of the appended claims. As is customary, the features shown in the accompanying drawings are not drawn to scale. The illustrations presented in this disclosure are not actual views of any particular device (such as an apparatus, system, etc.) or method, but are merely idealized schematic diagrams used to describe various examples of this disclosure. Therefore, the dimensions of the features may be arbitrarily enlarged or reduced for clarity. Furthermore, some figures may be simplified to improve clarity. Consequently, the figures may not depict all components of a given device (e.g., an apparatus) or all operations of a particular method.

[0228] The terms used herein, especially in the appended claims (e.g., the body of the claims), are generally intended to be “open-ended” terms (e.g., the term “comprising” should be interpreted as “including but not limited to”, the term “having” should be interpreted as “having at least”, the term “including” should be interpreted as “including but not limited to”, etc.).

[0229] Furthermore, if a limiting element introduced in a claim is intended to define a specific quantity, that intent will be explicitly stated in the claim; otherwise, the limiting intent does not exist. For example, for ease of understanding, appended claims may use introductory phrases such as "at least one" and "one or more" to introduce a limiting element. However, the use of such phrases should not be construed as implying that introducing a limiting element with the indefinite article "a" or "an" would limit any claim including that limiting element to only one example containing that limiting element, even if the same claim includes introductory phrases such as "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and / or "an" should be interpreted as "at least one" or "one or more"); the same principle of interpretation applies when using definite articles to introduce limiting elements.

[0230] Furthermore, even if the specific number of limiting elements introduced in the claims is explicitly stated, it should be understood that the limiting element should be interpreted as including at least the stated number (e.g., stating only "two limiting elements" without other modifications indicates at least two limiting elements, or more than two limiting elements). Additionally, when using expressions such as "at least one of A, B, and C" or "one or more of A, B, and C," such structures are generally intended to cover cases such as a single A, a single B, a single C, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C. For example, the use of the term "and / or" should be interpreted in this manner.

[0231] Furthermore, any extractive word or phrase presenting two or more alternative terms in the specification, claims, or drawings should be understood to cover the possibility of including one of the selected terms, another of the terms, or both terms simultaneously. For example, the phrase "A or B" should be understood to include the possibility of "A", "B", or "A and B".

[0232] Furthermore, the terms "first," "second," and "third," etc., used herein do not necessarily indicate a specific order or number of elements. Generally, the terms "first," "second," and "third," etc., are used as general identifiers to distinguish different elements. Unless otherwise specified, the terms "first," "second," and "third," etc., should not be construed as implying a specific order. Similarly, unless otherwise specified, the terms "first," "second," and "third," etc., should not be construed as implying a specific number of elements. For example, a first component may be described as having a first side, while a second component may be described as having a second side. Using the term "second side" for the second component may be to distinguish the side of the second component from the "first side" of the first component, rather than implying that the second component has two sides.

[0233] All examples and conditional language described herein are intended for pedagogical purposes to help readers understand the invention and the concepts contributed by the inventors to advance the technology, and should not be construed as limitations on these specific examples and conditions. Although examples of this disclosure have been described in detail, it should be understood that various changes, substitutions, and modifications can be made thereto without departing from the spirit and scope of this disclosure.

Claims

1. An access point (AP), comprising: The processing device is operable to: At the AP, the slave STA receives information about the interference path between the STA and the AP; At the AP, the transmit power is selected based on information about the interference path between the STA and the AP; At the AP, the transmission type is determined based on the transmit power, wherein the transmission type includes one or more of spatial multiplexing transmission or spatial null transmission; as well as The transceiver can be operated as follows: Based on the transmission type, a transmission is sent from the AP to the STA.

2. The AP of claim 1, wherein the information between the STA and the AP regarding the interference path includes one or more of the following: the transmit power backoff required for simultaneous transmission, or the maximum permissible transmit power of the AP.

3. The AP of claim 1, wherein the information between the STA and the AP regarding the interference path includes information for spatial nulling.

4. The AP according to claim 1, wherein the processing device is further operable to: At the AP, additional information regarding the additional interference path is received from another STA between the other STA and the AP; At the AP, the minimum transmit power is selected as the transmit power based on the following: Information between the STA and the AP regarding the interference path, and Additional information regarding the interference path between the other STA and the AP.

5. The AP according to claim 4, wherein the processing device is further operable to: The minimum transmit power is calculated based on the preamble received from the STA or one or more of the other STAs; or The minimum transmit power is calculated based on the minimum transmit power of the STA and the other STA.

6. The AP according to claim 1, wherein the processing device is further operable to: At the AP, the expected signal quality for spatial multiplexing transmission is calculated. The transceiver is operable to transmit the spatial multiplexing transmission when the expected signal quality for the signal multiplexing transmission is greater than a threshold.

7. The AP according to claim 1, wherein the processing device is further operable to: At the AP, when the transmit power required by the STA falls back to a threshold, the transmission type is determined to be spatial null transmission.

8. The AP according to claim 1, wherein the processing device is further operable to: At the AP, calculate the noise interference threshold; and The noise interference threshold is sent from the AP to the STA.

9. The AP according to claim 1, wherein the processing device is further operable to: At the AP, one or more of the following are selected: modulation coding scheme, or several spatial streams.

10. A station STA, comprising: The processing device is operable to: At the STA, a probe packet is received from an access point AP, wherein the AP is not associated with the STA; At the STA, calculate the coordinated spatial reuse C-SR feedback; as well as The transceiver can be operated as follows: The C-SR feedback is sent to the AP.

11. The STA of claim 10, wherein the C-SR feedback is one or more of the following: power back-off required by the STA, effective channel estimation from the AP to the STA, or signal and interference noise level.

12. The STA according to claim 10, wherein the processing apparatus is further operable to: At the STA, the permissible interference and noise levels are received from the AP; and At the STA, the required power backoff is calculated based on the permissible interference and noise levels.

13. The STA according to claim 10, wherein the processing apparatus is further operable to: At the STA, the permissible interference and noise levels are calculated. The transceiver is also operable to transmit the permissible interference and noise levels to the AP.

14. The STA according to claim 10, wherein the processing apparatus is further operable to: At the STA, when the secondary transmission is not activated, the increased noise and interference levels are simulated.

15. A coordination device, comprising: The processing device is operable to: The joint probe process is triggered when the coordinating device sends a joint probe to the first access point (AP); The joint detection process is triggered by the coordinating device sending the information to the second AP. At the coordinating device, a first detection feedback is received from the first AP; At the coordinating device, a second detection feedback is received from the second AP; At the coordination device, one or more of the following are determined: The transmit power of one or more of the first AP or the second AP; or The space null of one or more of the first AP or the second AP.

16. The coordination device of claim 15, wherein the coordination device is integrated with the first AP or the second AP.

17. The coordination device of claim 15, wherein the coordination device is separate from the first AP and the second AP.

18. The coordination device according to claim 15, wherein the processing device is further operable to: Identify one or more stations (STAs) to be served simultaneously; Associate the one or more STAs to the first AP or the second AP; or Calculate the transmit power of one or more of the first AP or the second AP.

19. The coordination device according to claim 15, wherein the processing device is further operable to: At the coordination device, one or more beamforming coefficients are calculated for one or more of the first AP or the second AP.

20. The coordination device according to claim 19, wherein the processing device is further operable to: At the coordinating device, using the one or more beamforming coefficients, spatial nulls are calculated for one or more of the first AP or the second AP.

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