Hybrid MU-MIMO spatial mapping using both explicit sounding and crosstalk tracking in a wireless local area network
Systems and methods for a wireless station supporting wireless communications with an associated wireless access point (WAP) on a wireless local area network (WLAN) where the wireless station can include hardware processing circuitry to perform hybrid spatial mapping feedback operations for multi-user (MU) multiple-input multiple-output (MIMO) downlinks from the WAP to a group of associated stations. An exemplary implementation includes a channel estimation circuit to determine a communication channel responsive to an explicit sounding from the WAP, and to transmit channel sounding feedback to the WAP indicating the determined communication channel; and a crosstalk tracking circuit to determine an amount of crosstalk from portions of a downlink MU-MIMO communication packet targeted for other stations in the group of associated stations, and to transmit crosstalk feedback to the WAP as to the determined amount of crosstalk.
1. A wireless station supporting wireless communications with an associated wireless access point (WAP) on a wireless local area network (WLAN); and the wireless station comprising:
hardware processing circuitry to perform hybrid spatial mapping feedback operations for multi-user (MU) multiple-input multiple-output (MIMO) downlinks from the WAP to a group of associated stations, including:
a channel estimation circuit to determine a communication channel responsive to an explicit sounding from the WAP, and to transmit channel sounding feedback to the WAP indicating the determined communication channel, wherein the WAP is to determine a precode matrix based on the sounding feedback; and
a crosstalk tracking circuit to determine an amount of crosstalk between portions of a spatially separated downlink MU-MIMO communication packet targeted for other stations in the group of associated stations, and to transmit crosstalk feedback to the WAP as to the determined amount of crosstalk, the WAP to make an adjustment to the precode matrix based on the crosstalk feedback.
2. The wireless station of claim 1 , wherein the crosstalk tracking circuit is further to conditionally transmit feedback to the WAP as to the determined crosstalk in response to determining the amount of the crosstalk exceeds a threshold level.
3. The wireless station of claim 1 , wherein the crosstalk feedback is to be transmitted in acknowledgment (ACK) packets.
4. The wireless station of claim 1 , wherein the crosstalk feedback is to be transmitted in at least one of a management frame, a data frame, or a control frame.
5. The wireless station of claim 1 , further to:
receive additional MU-MIMO downlink packets, wherein the additional MU-MIMO downlink packets are spatially mapped based on the adjusted precode matrix with a precode matrix “Q” adjusted in view of the channel sounding feedback and the crosstalk feedback.
6. The wireless station of claim 1 , further to:
receive additional MU-MIMO downlink packets spatially mapped by the WAP based on the adjusted precode matrix that has been adjusted using additional crosstalk feedback from the stations in the group.
7. The wireless station of claim 1 , further to:
receive additional MU-MIMO downlink packets spatially mapped by the WAP based on the adjusted precode matrix that has been adjusted using an offset matrix.
8. The wireless station of claim 7 , wherein the offset matrix is based on a channel estimation and interference channels at the other stations in the group.
9. The wireless station of claim 1 , further to:
receive additional MU-MIMO downlink packets spatially mapped by the WAP based on the adjusted precode matrix that has been adjusted using an offset matrix in view of additional crosstalk feedback from the stations in the group.
10. The wireless station of claim 1 , wherein the channel estimation circuit is further to determine channel state information based on a training field in downlink MU-MIMO communication packet.
11. The wireless station of claim 1 , wherein the amount crosstalk in determined based on estimating the channel state information in view of the channel sounding feedback to determine an interference contribution for each of the other stations in the group.
12. The wireless station of claim 1 , wherein transmitted crosstalk feedback includes a full crosstalk matrix as seen by the station.
13. The wireless station of claim 1 , further to:
indicate to the WAP a request for a next explicit sounding in response to determining the amount of crosstalk in view of a crosstalk threshold.
14. The wireless station of claim 1 , further to:
indicate to the WAP a request for a next explicit sounding in response to determining the amount of crosstalk in view of a performance metrics threshold.
15. The wireless station of claim 14 , wherein the performance metrics are at least one of a packet error rate (PER), signal-to-interference-plus-noise-ratio (SINR), or throughput metrics.
16. The wireless station of claim 1 , wherein the crosstalk tracking circuit further compresses the crosstalk feedback by decimating across subcarriers of the station.
17. The wireless station of claim 1 , wherein the crosstalk tracking circuit further compresses the crosstalk feedback by quantization of crosstalk matrix based on channel overhead metrics.
18. The wireless station of claim 1 , wherein the crosstalk feedback is compressed based on channel overhead metrics.
19. The wireless station of claim 1 , wherein the crosstalk feedback further includes an identifier of the group defined by the WAP associated with the sounding packet.
20. The wireless station of claim 19 , wherein two or more groups are associated with the WAP and the station is in more than one of the groups.
21. A method for operating a wireless station supporting wireless communications with an associated wireless access point (WAP) on a wireless local area network (WLAN); and the method comprising:
transmitting channel sounding feedback to the WAP in response to an explicit sounding from the WAP, wherein the WAP is to determine a precode matrix based on the sounding feedback; and
transmitting crosstalk feedback to the WAP in response to receipt of a multi-user (MU) MIMO downlink communication packet targeting a group of associated stations, the crosstalk feedback relating to crosstalk between two spatially separated portions of the packet, the WAP to make an adjustment to the precode matrix based on the crosstalk feedback.
22. The method of claim 21 , wherein transmitting the crosstalk feedback is via an acknowledgment (ACK) packets.
23. The method of claim 21 , further comprising:
receiving, by the station, additional MU-MIMO downlink packets spatially mapped by the WAP based on the adjusted precode matrix that has been adjusted using an offset matrix.
24. The method of claim 21 , wherein transmitting the crosstalk feedback to the WAP is further responsive to:
determining, by the station, an amount of crosstalk between portions of the MU-MIMO downlink packet targeted for other stations in the group of associated stations in view of a threshold.
25. The method of claim 21 , further comprising:
indicating to the WAP a request for a next explicit sounding in response to determining the amount of crosstalk in view of a crosstalk threshold.
26. The method of claim 21 , further comprising:
compressing the crosstalk feedback by decimating across subcarriers of the station.
27. The method of claim 21 , further comprising:
compressing the crosstalk feedback by quantization of crosstalk matrix based on channel overhead metrics.
28. The method of claim 21 , wherein the crosstalk feedback is compressed based on channel overhead metrics.
29. The method of claim 21 , wherein the crosstalk feedback further includes an identifier of the group defined by the WAP associated with the sounding packet.
30. The method of claim 21 , wherein two or more groups are associated with the WAP and the station is in more than one of the groups.
31. A method comprising:
a group of stations in communications with an associated wireless access point (WAP) on a wireless local area network (WLAN), wherein each station of the group transmitting channel sounding feedback to the WAP in response to an explicit sounding request to the group, wherein the WAP is to determine a precode matrix based on the sounding feedback; and
at least one station of the group transmitting crosstalk feedback to the WAP in response to receipt of a spatially separated multi-user (MU) MIMO downlink communication packet targeting the group of associated stations, the crosstalk feedback relating to crosstalk between two portions of the spatially separated packet, the WAP to make an adjustment to the precode matrix based on the crosstalk feedback.
32. The method of claim 31 , wherein two or more groups are associated with the WAP and the station is associated with more than one of the groups, wherein the crosstalk feedback further includes an identifier of the group defined by the WAP associated with the sounding packet.