Compressed feedback format for WLAN

1. A method comprising:

transmitting, from a first communication device, a sounding packet using one or more spatial or space-time streams and modulated using orthogonal frequency division multiplexing (OFDM);

receiving, at the first communication device, a feedback packet that was transmitted by a second communication device, the feedback packet including a feedback report corresponding to the sounding packet, the feedback report including

i) a plurality of angle values associated with the one or more spatial or space-time streams and one or more OFDM tones corresponding to the sounding packet,

ii) deltas corresponding to per-tone signal to noise ratio (PT-SNRs) associated with the one or more spatial or space-time streams and at least some of the one or more OFDM tones, wherein each delta corresponds to a difference between the respective PT-SNR and the an average signal to noise ratio (avg-SNR) associated with the one or more spatial or space-time streams, and

iii) the avg-SNR associated with the one or more spatial or space-time streams; and

using, at the first communication device, the feedback report to beamform transmissions to the second communication device.

2. The method of claim 1 , wherein:

the feedback report further includes an indication of a maximum number of spatial or space-time streams to use when transmitting to the second communication device; and

the method further comprises determining, at the first communication device, a number of spatial or space-time streams to use when transmitting to the second communication device.

3. The method of claim 1 , wherein:

the sounding packet is a first sounding packet;

the feedback packet is a first feedback packet;

the feedback report is a first feedback report corresponding to a multiuser (MU) mode;

the plurality of angle values is a plurality of first angle values;

the one or more spatial or space-time streams are a first one or more spatial or space-time streams; and

the method further comprises:

transmitting, from the first communication device, a second sounding packet using a second one or more spatial or space-time streams and modulated using OFDM, the second sounding packet corresponding to a single user (SU) mode,

receiving, at the first communication device, a second feedback packet that was transmitted by the second communication device, the second feedback packet including a second feedback report corresponding to the second sounding packet, the second feedback report including

i) a plurality of second angle values associated with the second one or more spatial or space-time streams and one or more OFDM tones corresponding to the second sounding packet, and

ii) an avg-SNR associated with the second one or more spatial or space-time streams, and

using, at the first communication device, the second feedback report to beamform transmissions to the second communication device in the SU mode.

4. The method of claim 1 , wherein the feedback packet includes:

a mode indicator field that indicates that the feedback report corresponds to a multiuser (MU) mode.

5. The method of claim 1 , further comprising:

determining, at the first communication device, an actual number of spatial or space-time streams to use when transmitting to the second communication device in a multiuser (MU) mode based on other feedback packets received from one or more third communication devices.

6. The method of claim 1 , further comprising:

jointly calculating, at the first communication device, a beamsteering matrix to be used when transmitting to the second communication and one or more third communication devices in a multiuser (MU) mode using information in the feedback report and information in one or more other feedback reports received from the one or more third communication devices.

7. The method of claim 1 , wherein the feedback packet further includes codebook information to indicate a number of bits used for quantizing each angle value of the plurality of angle values.

8. The method of claim 1 , wherein the first communication device is an access point.

9. The method of claim 7 , wherein the second communication device is a client of the access point.

10. The method of claim 1 , wherein the feedback packet further includes a modulation and coding scheme (MCS) feedback indicator.

11. The method of claim 1 , wherein the feedback report includes angle values and deltas corresponding to only one respective OFDM tone for multiple groups of OFDM tones.

12. A first communication device comprising:

a network interface device having one or more integrated circuit devices configured to:

cause the first communication device to transmit a sounding packet using one or more spatial or space-time streams and modulated using orthogonal frequency division multiplexing (OFDM),

process a feedback packet, the feedback packet having been transmitted by a second communication device and received at the first communication device, the feedback packet including a feedback report corresponding to the sounding packet, the feedback report including

i) a plurality of angle values associated with the one or more spatial or space-time streams and one or more OFDM tones corresponding to the sounding packet,

ii) deltas corresponding to per-tone signal to noise ratio (PT-SNRs) associated with the one or more spatial or space-time streams and at least some of the one or more OFDM tones, wherein each delta corresponds to a difference between the respective PT-SNR and the an average signal to noise ratio (avg-SNR) associated with the one or more spatial or space-time streams, and

iii) the avg-SNR associated with the one or more spatial or space-time streams, and

use the feedback report to beamform transmissions to the second communication device.

13. The first communication device of claim 12 , wherein:

the feedback report further includes an indication of a maximum number of spatial or space-time streams to use when transmitting to the second communication device; and

the one or more integrated circuit devices are further configured to determine a number of spatial or space-time streams to use when transmitting to the second communication device.

14. The first communication device of claim 12 , wherein:

the sounding packet is a first sounding packet;

the feedback packet is a first feedback packet;

the feedback report is a first feedback report corresponding to a multiuser (MU) mode;

the plurality of angle values is a plurality of first angle values;

the one or more spatial or space-time streams are a first one or more spatial or space-time streams; and

the one or more integrated circuit devices are further configured to:

cause the first communication device to transmit a second sounding packet using a second one or more spatial or space-time streams and modulated using OFDM, the second sounding packet corresponding to a single user (SU) mode,

process a second feedback packet, the second feedback packet having been transmitted by the second communication device and received at the first communication device, the second feedback packet including a second feedback report corresponding to the second sounding packet, the second feedback report including

i) a plurality of second angle values associated with the second one or more spatial or space-time streams and one or more OFDM tones corresponding to the second sounding packet, and

ii) an avg-SNR associated with the second one or more spatial or space-time streams, and

use the second feedback report to beamform transmissions to the second communication device in the SU mode.

15. The first communication device of claim 12 , wherein the feedback packet includes:

a mode indicator field that indicates that the feedback report corresponds to a multiuser (MU) mode.

16. The first communication device of claim 12 , wherein the one or more integrated circuit devices are further configured to:

determine an actual number of spatial or space-time streams to use when transmitting to the second communication device in a multiuser (MU) mode based on other feedback packets received, at the first communication device, from one or more third communication devices.

17. The first communication device of claim 12 , wherein the one or more integrated circuit devices are further configured to:

jointly calculate a beamsteering matrix to be used when transmitting to the second communication and one or more third communication devices in a multiuser (MU) mode using information in the feedback report and information in one or more other feedback reports received from the one or more third communication devices.

18. The first communication device of claim 12 , wherein the feedback packet further includes codebook information to indicate a number of bits used for quantizing each angle value of the plurality of angle values.

19. The first communication device of claim 12 , wherein the first communication device is an access point.

20. The first communication device of claim 19 , wherein the second communication device is a client of the access point.

21. The first communication device of claim 12 , wherein the feedback packet further includes a modulation and coding scheme (MCS) feedback indicator.

22. A tangible, non-transitory computer readable medium having stored thereon computer executable instructions that, when executed by a processor, cause the processor to:

cause a first communication device to transmit a sounding packet using one or more spatial or space-time streams and modulated using orthogonal frequency division multiplexing (OFDM),

process a feedback packet, the feedback packet having been transmitted by a second communication device and received at the first communication device, the feedback packet including a feedback report corresponding to the sounding packet, the feedback report including

i) a plurality of angle values associated with the one or more spatial or space-time streams and one or more OFDM tones corresponding to the sounding packet,

ii) deltas corresponding to per-tone signal to noise ratio (PT-SNRs) associated with the one or more spatial or space-time streams and at least some of the one or more OFDM tones, wherein each delta corresponds to a difference between the respective PT-SNR and the an average signal to noise ratio (avg-SNR) associated with the one or more spatial or space-time streams, and

iii) the avg-SNR associated with the one or more spatial or space-time streams, and

use the feedback report to beamform transmissions to the second communication device.