Calibration correction for implicit beamforming in a wireless MIMO communication system

1. A method, comprising:

determining, at a first transceiver device, a partial dimensional description of a reverse multiple input, multiple output (MIMO) channel based on a reception of a first packet received from a second transceiver device via the reverse MIMO channel, wherein the first packet includes training information of spatial dimensions used for the transmission of the first packet but does not include training information for all available spatial dimensions of the reverse MIMO channel, wherein the reverse MIMO channel corresponds to a signal direction from the second transceiver device to the first transceiver device;

developing, at the first transceiver device, a correction matrix from (i) the partial dimensional description of the reverse MIMO channel and (ii) a description of a forward MIMO channel, wherein the forward MIMO channel corresponds to a signal direction from the first transceiver device to the second transceiver device; and

using, at the first transceiver device, the correction matrix to process signals to be transmitted via the forward MIMO channel.

2. A method according to claim 1 , further comprising:

causing, at the first transceiver device, a second packet to be transmitted via the forward MIMO channel, wherein the second packet includes a request to initiate calibration.

3. A method according to claim 2 , wherein the first packet is an acknowledgment of the second packet.

4. A method according to claim 1 , further comprising receiving the description of the forward MIMO channel from the second transceiver device.

5. A method according to claim 4 , wherein receiving the description of the forward MIMO channel comprises receiving channel state information via a second packet.

6. A method according to claim 4 , further comprising causing, at the first transceiver device, a second packet to be transmitted via the forward MIMO channel, wherein

the second packet includes training information for all available spatial dimensions of the forward MIMO channel, and

the second packet is configured to prompt the second transceiver device to transmit the description of the forward MIMO channel to the first transceiver device.

7. A method according to claim 1 , wherein determining the partial dimensional description of the reverse MIMO channel comprises determining the partial dimensional description of the reverse MIMO channel without determining a full dimensional description of the reverse MIMO channel.

8. A method according to claim 1 , wherein determining the partial dimensional description of the reverse MIMO channel comprises determining a subset of columns of a matrix corresponding to a full-dimensional description of the reverse MIMO channel.

9. A method according to claim 8 , wherein developing the correction matrix comprises:

determining a respective correction matrix estimate for each column in the subset of columns of the matrix corresponding to the full-dimensional description of the reverse MIMO channel; and

generating the correction matrix using the respective correction matrix estimates.

10. A method according to claim 8 , wherein developing the correction matrix comprises:

calculating a first singular value decomposition corresponding to the subset of columns of the matrix corresponding to the full-dimensional description of the reverse MIMO channel;

determining a subset of rows of a matrix corresponding to the description of the forward MIMO channel;

calculating a second singular value decomposition corresponding to the subset of rows of the matrix corresponding to the description of the forward MIMO channel; and

generating the correction matrix based on the first singular value decomposition and the second singular value decomposition.

11. A method according to claim 8 , wherein developing the correction matrix comprises:

calculating a first right singular matrix corresponding to the subset of columns of the matrix corresponding to the full-dimensional description of the reverse MIMO channel;

determining a subset of rows of a matrix corresponding to the description of the forward MIMO channel;

calculating a second right singular matrix corresponding to the subset of rows of the matrix corresponding to the description of the forward MIMO channel; and

generating the correction matrix based on the first right singular matrix and the second right singular matrix.

12. A tangible, non-transitory computer readable medium or media storing machine readable instructions that, when executed by one or more processors, cause the one or more processors to:

determine a partial dimensional description of a reverse multiple input, multiple output (MIMO) channel based on a reception of a first packet received from a second transceiver device via the reverse MIMO channel, wherein the first packet includes training information of spatial dimensions used for the transmission of the first packet but does not include training information for all available spatial dimensions of the reverse MIMO channel, wherein the reverse MIMO channel corresponds to a signal direction from the second transceiver device to a first transceiver device;

develop a correction matrix from (i) the partial dimensional description of the reverse MIMO channel and (ii) a description of a forward MIMO channel, wherein the forward MIMO channel corresponds to a signal direction from the first transceiver device to the second transceiver device; and

use the correction matrix to process signals to be transmitted via the forward MIMO channel.

13. A tangible, non-transitory computer readable medium or media according to claim 12 , further storing machine readable instructions that, when executed by the one or more processors, cause the one or more processors to:

cause a second packet to be transmitted via the forward MIMO channel, wherein the second packet includes a request to initiate calibration.

14. A tangible, non-transitory computer readable medium or media according to claim 12 , wherein the description of the forward MIMO channel is received from the second transceiver device.

15. A tangible, non-transitory computer readable medium or media according to claim 14 , wherein the description of the forward MIMO channel corresponds to channel state information received in a second packet.

16. A tangible, non-transitory computer readable medium or media according to claim 14 , further storing machine readable instructions that, when executed by the one or more processors, cause the one or more processors to cause a second packet to be transmitted via the forward MIMO channel, wherein

the second packet includes training information for all available spatial dimensions of the forward MIMO channel, and

the second packet is configured to prompt the second transceiver device to transmit the description of the forward MIMO channel to the first transceiver device.

17. A tangible, non-transitory computer readable medium or media according to claim 12 , further storing machine readable instructions that, when executed by the one or more processors, cause the one or more processors to determine the partial dimensional description of the reverse MIMO channel without determining a full dimensional description of the reverse MIMO channel.

18. A tangible, non-transitory computer readable medium or media according to claim 12 , further storing machine readable instructions that, when executed by the one or more processors, cause the one or more processors to determine the partial dimensional description of the reverse MIMO channel at least by determining a subset of columns of a matrix corresponding to a full-dimensional description of the reverse MIMO channel.

19. A tangible, non-transitory computer readable medium or media according to claim 18 , further storing machine readable instructions that, when executed by the one or more processors, cause the one or more processors to develop the correction matrix at least by:

determining a respective correction matrix estimate for each column in the subset of columns of the matrix corresponding to the full-dimensional description of the reverse MIMO channel; and

generating the correction matrix using the respective correction matrix estimates.

20. A tangible, non-transitory computer readable medium or media according to claim 18 , further storing machine readable instructions that, when executed by the one or more processors, cause the one or more processors to develop the correction matrix at least by:

calculating a first singular value decomposition corresponding to the subset of columns of the matrix corresponding to the full-dimensional description of the reverse MIMO channel;

determining a subset of rows of a matrix corresponding to the description of the forward MIMO channel;

calculating a second singular value decomposition corresponding to the subset of rows of the matrix corresponding to the description of the forward MIMO channel; and

generating the correction matrix based on the first singular value decomposition and the second singular value decomposition.

21. A tangible, non-transitory computer readable medium or media according to claim 18 , further storing machine readable instructions that, when executed by the one or more processors, cause the one or more processors to develop the correction matrix at least by:

calculating a first right singular matrix corresponding to the subset of columns of the matrix corresponding to the full-dimensional description of the reverse MIMO channel;

determining a subset of rows of a matrix corresponding to the description of the forward MIMO channel;

calculating a second right singular matrix corresponding to the subset of rows of the matrix corresponding to the description of the forward MIMO channel; and

generating the correction matrix based on the first right singular matrix and the second right singular matrix.