Sub-band feedback for beamforming on downlink multiple user MIMO configurations

1. A method in a communication network, the method comprising:

receiving, at a first communication device, a sounding packet, wherein the sounding packet was transmitted by a second communication device over a communication channel such that the sounding packet spans an entire bandwidth of the communication channel;

performing, at the first communication device, a channel estimation on a subchannel block of the communication channel, based on reception of the sounding packet, to determine steering matrix feedback information for the subchannel block, wherein the subchannel block spans a contiguous partial bandwidth of the communication channel and does not span the entire bandwidth of the communication channel, and wherein the steering matrix feedback information does not include steering matrix feedback information for one or more other subchannel blocks of the communication channel that respectively span one or more other respective contiguous partial bandwidths of the communication channel; and

transmitting, by the first communication device, a communication frame to the second communication device, the communication frame i) including the steering matrix feedback information for the subchannel block, and ii) not including steering matrix feedback information for the one or more other subchannel blocks of the communication channel.

2. The method of claim 1 , wherein the sounding packet is a null data packet (NDP) sounding packet.

3. The method of claim 1 , wherein:

the steering matrix feedback information for the subchannel block includes information corresponding to a compressed steering matrix that corresponds to the subchannel block; and

the communication frame includes the information corresponding to the compressed steering matrix.

4. The method of claim 1 , wherein:

the steering matrix feedback information for the subchannel block includes information corresponding to an uncompressed steering matrix that corresponds to the subchannel block; and

the communication frame includes the information corresponding to the uncompressed steering matrix.

5. The method of claim 1 , wherein one of:

a packet bandwidth of the sounding packet is 40 megahertz (MHz) and the subchannel block spans 20 MHz;

the packet bandwidth of the sounding packet is 80 MHz and the subchannel block spans 40 MHz;

the packet bandwidth of the sounding packet is 160 MHz and the subchannel block spans 80 MHz; or

the packet bandwidth of the sounding packet is 160 MHz and the subchannel block spans 40 MHz.

6. An apparatus, comprising:

a transceiver associated with a first communication device, wherein the transceiver is implemented on one or more integrated circuit (IC) devices, and wherein the transceiver is configured to:

receive a sounding packet, wherein the sounding packet was transmitted by a second communication device over a communication channel such that the sounding packet spans an entire bandwidth of the communication channel;

a channel estimation circuit associated with the first communication device, wherein the channel estimation circuit is implemented on the one or more IC devices, and wherein the channel estimation circuit is configured to:

perform a channel estimation on a subchannel block of the communication channel, based on reception of the sounding packet, to determine steering matrix feedback information for the subchannel block, wherein the subchannel block spans a contiguous partial bandwidth of the communication channel and does not span the entire bandwidth of the communication channel, and wherein the steering matrix feedback information does not include steering matrix feedback information for one or more other subchannel blocks of the communication channel that respectively span one or more other respective contiguous partial bandwidths of the communication channel;

wherein the transceiver is further configured to:

transmit a communication frame to the second communication device, the communication frame i) including the steering matrix feedback information for the subchannel block, and ii) not including steering matrix feedback information for the one or more other subchannel blocks of the communication channel.

7. The apparatus of claim 6 , wherein the sounding packet is a null data packet (NDP) sounding packet.

8. The apparatus of claim 6 , wherein:

the steering matrix feedback information for the subchannel block includes information corresponding to a compressed steering matrix that corresponds to the subchannel block; and

the communication frame includes the information corresponding to the compressed steering matrix.

9. The apparatus of claim 6 , wherein:

the steering matrix feedback information for the subchannel block includes information corresponding to an uncompressed steering matrix that corresponds to the subchannel block; and

the communication frame includes the information corresponding to the uncompressed steering matrix.

10. The apparatus of claim 6 , wherein one of:

a packet bandwidth of the sounding packet is 40 megahertz (MHz) and the subchannel block spans 20 MHz;

the packet bandwidth of the sounding packet is 80 MHz and the subchannel block spans 40 MHz;

the packet bandwidth of the sounding packet is 160 MHz and the subchannel block spans 80 MHz; or

the packet bandwidth of the sounding packet is 160 MHz and the subchannel block spans 40 MHz.

11. A method, comprising:

transmitting, by a first communication device, a sounding packet to a second communication device over a communication channel such that the sounding packet spans an entire bandwidth of the communication channel;

receiving, at the first communication device, a communication frame from the second communication device, the communication frame responsive to the sounding packet, the communication frame including steering matrix feedback information for a subchannel block of the communication channel, wherein:

the subchannel block spans a contiguous partial bandwidth of the communication channel and does not span the entire bandwidth of the communication channel, and

the communication frame does not include steering matrix feedback information for one or more other subchannel blocks of the communication channel that respectively span one or more other respective contiguous partial bandwidths of the communication channel;

using, at the first communication device, the steering matrix feedback information for the subchannel block to identify a steering matrix for use in transmitting to the second communication device; and

applying, at the first communication device, the identified steering matrix to only a portion, in frequency, of an information carrying packet, wherein the portion, in frequency, of the information carrying packet corresponds, in frequency, to the subchannel block, and does not correspond, in frequency to the one or more other subchannel blocks of the communication channel.

12. The method of claim 11 , wherein the sounding packet is a null data packet (NDP) sounding packet.

13. The method of claim 11 , wherein:

the steering matrix feedback information for the subchannel block includes information corresponding to a compressed steering matrix that corresponds to the subchannel block; and

using the steering matrix feedback information for the subchannel block to identify the steering matrix comprises using the information corresponding to the compressed steering matrix to identify the steering matrix for use in transmitting to the second communication device.

14. The method of claim 11 , wherein:

the steering matrix feedback information for the subchannel block includes information corresponding to an uncompressed steering matrix that corresponds to the subchannel block; and

using the steering matrix feedback information for the subchannel block to identify the steering matrix comprises adopting the uncompressed steering matrix as the steering matrix for use in transmitting to the second communication device.

15. The method of claim 11 , wherein one of:

a packet bandwidth of the sounding packet is 40 megahertz (MHz) and the subchannel block spans 20 MHz;

the packet bandwidth of the sounding packet is 80 MHz and the subchannel block spans 40 MHz;

the packet bandwidth of the sounding packet is 160 MHz and the subchannel block spans 80 MHz; or

the packet bandwidth of the sounding packet is 160 MHz and the subchannel block spans 40 MHz.

16. An apparatus, comprising:

a network interface device associated with a first communication device, wherein the network interface device is implemented on one or more integrated circuit (IC) devices, and wherein the network interface device configured to:

transmit, via a plurality of antennas, a sounding packet to a second communication device over a communication channel such that the sounding packet spans an entire bandwidth of the communication channel, and

receive a communication frame from the second communication device, the communication frame responsive to the sounding packet, the communication frame including steering matrix feedback information for a subchannel block of the communication channel, wherein:

the subchannel block spans a contiguous partial bandwidth of the communication channel and does not span the entire bandwidth of the communication channel, and

the communication frame does not include steering matrix feedback information for one or more other subchannel blocks of the communication channel that respectively span one or more other respective contiguous partial bandwidths of the communication channel;

wherein the network interface device includes a steering vector controller implemented on the one or more ICs, the steering vector controller configured to use the steering matrix feedback information to identify a steering matrix for use in transmitting to the second communication device; and

wherein the network interface device further includes a spatial steering controller implemented on the one or more ICs, the spatial steering controller configured to apply the identified steering matrix to only a portion, in frequency, of an information carrying packet to be transmitted by the first communication device, wherein the portion, in frequency, of the information carrying packet corresponds, in frequency, to the subchannel block, and does not correspond, in frequency to the one or more other subchannel blocks of the communication channel.

17. The apparatus of claim 16 , wherein the sounding packet is a null data packet (NDP) sounding packet.

18. The apparatus of claim 16 , wherein:

the steering matrix feedback information for the subchannel block includes information corresponding to a compressed steering matrix that corresponds to the subchannel block; and

the steering vector controller configured to use the information corresponding to the compressed steering matrix to identify the steering matrix for use in transmitting to the second communication device.

19. The apparatus of claim 16 , wherein:

the steering matrix feedback information for the subchannel block includes information corresponding to an uncompressed steering matrix that corresponds to the subchannel block; and

the steering vector controller configured to adopt the uncompressed steering matrix as the steering matrix for use in transmitting to the second communication device.

20. The apparatus of claim 16 , wherein one of:

a packet bandwidth of the sounding packet is 40 megahertz (MHz) and the subchannel block spans 20 MHz;

the packet bandwidth of the sounding packet is 80 MHz and the subchannel block spans 40 MHz;

the packet bandwidth of the sounding packet is 160 MHz and the subchannel block spans 80 MHz; or

the packet bandwidth of the sounding packet is 160 MHz and the subchannel block spans 40 MHz.