Sounding and tone block allocation for orthogonal frequency multiple access (OFDMA) in wireless local area networks

1. A method for simultaneously communicating with multiple communication devices in a communication network, the method comprising:

receiving, at a first communication device, sounding feedback packets from a plurality of second communication devices, wherein each sounding feedback packet includes (i) beamforming feedback to be used by the first communication device for beamforming to the corresponding second communication device and (ii) one or more quality indicators corresponding to one or more sub-channel blocks of an orthogonal frequency division multiplexing (OFDM) communication channel associated with the corresponding second communication device;

selecting, at the first communication device based on the one or more quality indicators received from each of at least some of the second communication devices, a group of second communication devices for orthogonal frequency division multiple access (OFDMA) communication, wherein the group includes two or more second communication devices of the plurality of second communication devices; and

transmitting, from the first communication device to the group of second communication devices, at least one OFDMA data unit that includes respective OFDM data units directed to the two or more second communication devices of the group, wherein the respective OFDM data units are transmitted in respective sub-channel blocks allocated to the two or more second communication devices of the group.

2. The method of claim 1 , further comprising prior to receiving the sounding feedback packets, transmitting a sounding packet from the first communication device to the plurality of second communication devices, wherein the sounding feedback packets are transmitted by the plurality of second communication devices in response to receiving the sounding packet.

3. The method of claim 1 , wherein the one or more quality indicators corresponding to one or more sub-channel blocks of the OFDM communication channel associated with the second communication device include one or both of (i) indications of one or more preferred sub-channel blocks for the second communication device and (ii) indications of order of preference of multiple preferred sub-channel blocks for the second communication device.

4. The method of claim 1 , further comprising, prior to transmitting the at least one OFDMA data unit to the group of second communication devices, transmitting a group management frame to indicate to the second communication devices of the group that the second communication devices are members of the group.

5. The method of claim 1 , further comprising allocating, based on the quality indicators obtained for the two or more second communication devices of the group, the respective sub-channel blocks to the two or more second communication devices of the group.

6. The method of claim of claim 5 , further comprising:

after transmitting the at least one OFDMA data unit to the group of second communication devices, obtaining, for each of the second communication devices of the group, one or more new quality indicators corresponding to one or more sub-channel blocks of the OFDM communication channel associated with the second communication device,

allocating respective sub-channel blocks to the second communication devices of the group based on the new quality indicators, and

transmitting at least one additional OFDMA data unit that includes respective OFDM data units directed to the two or more second communication devices of the group, wherein the respective OFDM data units are transmitted in respective sub-channel blocks allocated to the two or more second communication devices based on the new quality indicators.

7. An apparatus for use in a communication system, the apparatus comprising:

a network interface comprising one or more integrated circuits configured to

receive sounding feedback packets from a plurality of communication devices, wherein each sounding feedback packet includes (i) beamforming feedback to be used for beamforming to the corresponding communication device and (ii) one or more quality indicators corresponding to one or more sub-channel blocks of an orthogonal frequency division multiplexing (OFDM) communication channel associated with the corresponding communication device;

select, based on the one or more quality indicators received from each of at least some communication devices of the plurality of communication devices, a group of communication devices for orthogonal frequency division multiple access (OFDMA) communication, wherein the group includes two or more communication devices of the plurality of communication devices; and

transmit, to the group of communication devices, at least one OFDMA data unit that includes respective OFDM data units directed to the two or more communication devices of the group, wherein the respective OFDM data units are transmitted in respective sub-channel blocks allocated to the two or more communication devices of the group.

8. The apparatus of claim 7 , wherein the one or more integrated circuits are further configured to:

prior to receiving the sounding feedback packets, transmit a sounding packet to the plurality of communication devices, wherein the sounding feedback packets are transmitted by the plurality of communication devices in response to receiving the sounding packet.

9. The apparatus of claim 7 , wherein the one or more quality indicators corresponding to one or more sub-channel blocks of the OFDM communication channel associated with the communication device include one or both of (i) indications of one or more preferred sub-channel blocks for the communication device and (ii) indications of order of preference of multiple preferred sub-channel blocks for the communication device.

10. The apparatus of claim 7 , wherein the one or more integrated circuits are further configured to, prior to transmitting the at least one OFDMA data unit to the group of communication devices, transmit a group management frame to indicate to the communication devices of the group that the communication devices are members of the group.

11. The apparatus of claim 7 , wherein the one or more integrated circuits are further configured to allocate, based on the quality indicators obtained for the two or more communication devices of the group, the respective sub-channel blocks to the two or more communication devices of the group.

12. The apparatus of claim 11 , wherein the one or more integrated circuits are further configured to:

after transmitting the at least one OFDMA data unit to the group of communication devices, obtain, for each of the communication devices of the group, one or more new quality indicators corresponding to one or more sub-channel blocks of the OFDM communication channel associated with the communication device,

allocate respective sub-channel blocks to the communication devices of the group based on the new quality indicators, and

transmit at least one additional OFDMA data unit that includes respective OFDM data units directed to the two or more communication devices of the group, wherein the respective OFDM data units are transmitted in respective sub-channel blocks allocated to the two or more communication devices based on the new quality indicators.