Alternate feedback types for downlink multiple user MIMO configurations
A method in a communication network includes obtaining descriptions of a plurality of communication channels each communication channel associated with a different one of a plurality of receivers; and generating a plurality of steering vectors, one for each of the plurality of receivers, using the descriptions of the plurality of communication channels; wherein each steering vector is used to transmit data to a corresponding one of the plurality receivers via a plurality of antennas and over a corresponding one of the communication channels simultaneously and wherein each steering vector is used to communicate data on a different one of the plurality of communication channels, and wherein each steering vector is generated to reduce interference on a corresponding communication channel caused by simultaneous transmission of data on other communication channels.
1. A method, comprising:
receiving, at an access point device, a plurality of beamsteering feedback frames from a plurality of client devices in connection with a procedure for generating respective steering matrices for performing multiple user communications with the plurality of client devices, including receiving a first beamsteering feedback frame from a first client device, the first beamsteering feedback frame including i) first compressed beamsteering information corresponding to a first communication channel between the access point device and the first client device and ii) an indication of a preferred number of streams to be used when the access point performs single user beamformed communications with the first client device;
generating, at the access point device, the respective steering matrices using compressed beamforming information included in the plurality of beamsteering feedback frames, including using the first compressed beamsteering information to generate a first steering matrix for transmitting to the first client device as part of a multiple user beamformed transmission to the plurality of client devices;
generating, at the access point device, a second steering matrix for transmitting to the first client device as part of a single user beamformed transmission using the first compressed beamsteering information; and
using, at the access point device, the indication of the preferred number of streams in the first beamsteering feedback frame to determine how many streams to utilize when transmitting to the first client device as part of a single user beamformed transmission.
2. The method of claim 1 , wherein:
the first compressed beamsteering information includes a first compressed beamsteering matrix; and
the first beamsteering feedback frame further includes an indication of a number of columns of the first compressed beamsteering matrix.
3. The method of claim 1 , wherein:
the first compressed beamsteering information includes a first compressed beamsteering matrix corresponding to a singular value decomposition (SVD) of a channel estimation matrix corresponding to the first communication channel between the access point device and the first client device.
4. The method of claim 1 , wherein:
receiving the plurality of beamsteering feedback frames from the plurality of client devices further includes receiving one or more second beamsteering feedback frames from one or more second client devices, the one or more second beamsteering feedback frames including one or more respective second compressed beamsteering information corresponding to one or more respective second communication channels between the access point device and the one or more respective second client devices; and
generating the first steering matrix includes using the one or more respective second compressed beamsteering information in order to reduce interference to the one or more respective second client devices when using the first steering matrix to transmit to the first client device as part of the multiple user beamformed transmission to the plurality of client devices.
5. The method of claim 1 , further comprising:
transmitting, by the access point device, a sounding packet to the plurality of client devices;
wherein the plurality of beamsteering feedback frames from the plurality of client devices include compressed beamsteering information determined by the plurality of client devices based on reception of the sounding packet at the plurality of client devices.
6. An apparatus, comprising:
a wireless network interface device of an access point device, the wireless network interface device configured to receive a plurality of beamsteering feedback frames from a plurality of client devices in connection with a procedure for generating respective steering matrices for performing multiple user communications with the plurality of client devices, including receiving a first beamsteering feedback frame from a first client device, the first beamsteering feedback frame including i) first compressed beamsteering information corresponding to a first communication channel between the access point device and the first client device and ii) an indication of a preferred number of streams to be used when the access point performs single user beamformed communications with the first client device;
wherein the wireless network interface device includes a steering matrix controller configured to:
generate the respective steering matrices using compressed beamforming information included in the plurality of beamsteering feedback frames, including using the first compressed beamsteering information to generate a first steering matrix for transmitting to the first client device as part of a multiple user beamformed transmission to the plurality of client device, and
generate a second steering matrix for transmitting to the first client device as part of a single user beamformed transmission using the first compressed beamsteering information; and
wherein the wireless network interface device is further configured to use the indication of the preferred number of streams in the first beamsteering feedback frame to determine how many streams to utilize when transmitting to the first client device as part of a single user beamformed transmission.
7. The apparatus of claim 6 , wherein:
the first compressed beamsteering information includes a first compressed beamsteering matrix; and
the first beamsteering feedback frame further includes an indication of a number of columns of the first compressed beamsteering matrix.
8. The apparatus of claim 6 , wherein:
the first compressed beamsteering information includes a first compressed beamsteering matrix corresponding to a singular value decomposition (SVD) of a channel estimation matrix corresponding to the first communication channel between the access point device and the first client device.
9. The apparatus of claim 6 , wherein:
the wireless network interface device is further configured to receive one or more second beamsteering feedback frames from one or more second client devices, the one or more second beamsteering feedback frames including one or more respective second compressed beamsteering information corresponding to one or more respective second communication channels between the access point device and the one or more respective second client devices; and
the steering matrix controller is further configured to use the one or more respective second compressed beamsteering information to generate the first steering matrix in order to reduce interference to the one or more respective second client devices when using the first steering matrix to transmit to the first client device as part of the multiple user beamformed transmission to the plurality of client devices.
10. The apparatus of claim 6 , wherein:
the wireless network interface device is further configured to transmit a sounding packet to the plurality of client devices;
wherein the plurality of beamsteering feedback frames from the plurality of client devices include compressed beamsteering information determined by the plurality of client devices based on reception of the sounding packet at the plurality of client devices.
11. The apparatus of claim 6 , wherein wireless network interface device comprises a plurality of transceivers.
12. The apparatus of claim 11 , further comprising:
a plurality of antennas coupled to the plurality of transceivers.