Channel estimation using a multi-user frame

1. A method of channel estimation, the method comprising:

determining, by a transmitter, a number of receivers with which to communicate a frame wirelessly, the number of receivers being at least one and corresponding to at least a first receiver; and

generating, by the transmitter, the frame to transmit to the first receiver, the frame being generated based on a total number of receivers that is higher than the determined number of receivers, wherein the frame comprises at least one copy of at least one first-type training field, wherein a number of the at least one copy of the at least one first-type training field plus a number of the at least one first-type training field is equal to the total number of receivers that is higher than the determined number of receivers.

2. The method of claim 1 , further comprising determining that the first receiver supports multi-user multiple-input and multiple-output (MU-MIMO) frames.

3. The method of claim 1 , wherein the frame is a multi-user multiple-input and multiple-output (MU-MIMO) frame.

4. The method of claim 1 , wherein the first-type training field and the at least one copy are used by the receiver to perform noise averaging.

5. The method of claim 1 , wherein the total number of receivers is at least twice the determined number of receivers.

6. The method of claim 1 , wherein the first-type frame training field comprise a very high throughput long training field (VHT-LTF) for performing channel estimation, wherein the at least one copy is sign modulated.

7. The method of claim 1 , further comprising identifying at least one receiver from the total number of receivers that does not physically exist, and performing transmission steering without assigning one or more of: transmission power and data, to the at least one identified receiver that does not physically exist.

8. The method of claim 7 , further comprising generating a steering matrix for the transmitter with appropriately zeroed entries corresponding to the at least one identified receiver.

9. The method of claim 1 , further comprising determining a channel estimation response in the receiver, the channel estimation response generated based on multiple copies of a value provided in the frame for performing channel estimation.

10. The method of claim 1 , further comprising receiving one or more of: location and time of flight feedback from the receiver determined based on the frame.

11. A wireless beamformer device, comprising:

a processor configured to provide a frame to transmit to at least a first wireless beamformee device, the processor configured to provide the frame based on a total number of beamformee devices that is higher than a total number of intended recipients, wherein the frame comprises at least one copy of at least one first-type training field, wherein a number of the at least one copy of the at least one first-type training field plus a number of the at least one first-type training field is equal to the total number of beamformee devices that is higher than the total number of intended recipients.

12. The wireless beamformer device of claim 11 , wherein the frame comprises a multi-user multiple-input and multiple-output (MU-MIMO) frame and wherein the processor has data indicating that the first wireless beamformee device supports multiple unit beamforming.

13. The wireless beamformer device of claim 11 , wherein the first-type training field is used to perform noise averaging.

14. The wireless beamformer device of claim 13 , wherein the wireless beamformer device is an 802.11 standard device and the at least one copy comprises at least one sign modulated copy.

15. The wireless beamformer device of claim 11 , wherein the frame comprises the at least on copy is a very high throughput long training field (VHT-LTF) field for performing channel estimation.

16. The wireless beamformer device of claim 11 , wherein the processor is configured to determine a size of the frame and to provide the frame generated based on the total number of beamformee devices that is higher than the total number intended recipients, responsive to determining that the size is in a first relationship to a threshold.

17. The wireless beamformer device of claim 16 , wherein the processor is configured to provide the frame generated based on the total number of beamformee devices that is the same as the total number of intended recipients, responsive to determining that the size is in a second relationship to the threshold.

18. A method of wireless communication, the method comprising:

determining, by a beamformer, a number of beamformees supporting multiple unit beamforming and intended by the beamformer to receive a frame; and

providing, by the beamformer, the frame to transmit based on a total number of beamformees that is higher than the determined number of the beamformees intended by the beamformer to receive the frame, the frame including a number of fields for multiple unit beamforming training, the number of fields for multiple unit beamforming training being more than the determined number of beamformees intended by the beamformer to receive the frame, wherein the frame comprises at least one copy of at least one first-type training field, wherein a number of the at least one copy of the at least one first-type training field plus a number of the at least one first-type training field is equal to the total number of the beamformees that is higher than the number of beamformees intended by the beamformer to receive the frame.

19. The method of claim 18 , further comprising receiving a channel estimation response from a beamformee, the channel estimation response generated based on at least one copy of a field in the number of fields, the total number of fields including the at least one copy, the at least one copy and the field being used for performing channel estimation.

20. The method of claim 18 , wherein the beamformer is an access point for a wireless local area network.