Method for channel sounding in wireless local area network and apparatus for the same

Abstract

A method, performed by a transceiver, is described. The transceiver receives a null data packet announcement (NDPA) frame to initiate channel sounding and a null data packet (NDP), the NDP following the NDPA frame. A first report field including beamforming information and a second report field including signal to noise ratio (SNR) information is configured. First feedback data including the first report field and a second report field is split into a plurality of segments. The plurality of segments is transmitted in a single aggregated medium access control protocol data unit (A-MPDU) including MPDUs. A retransmission request including a segment retransmission bitmap field indicating at least one segment of the plurality of segments for retransmission is received. In response to the retransmission request, second feedback data including the at least one segment indicated by the segment retransmission bitmap field is transmitted.

What is claimed is: 
     
       1. A method for channel sounding in a wireless local area network, the method performed by a transceiver and comprising:
 receiving a null data packet announcement (NDPA) frame from a transmitter to initiate the channel sounding; 
 receiving a null data packet (NDP) from the transmitter, the NDP following the NDPA frame; 
 configuring a first report field including beamforming information and a second report field including signal to noise ratio (SNR) information; 
 splitting first feedback data including the first report field and the second report field into a plurality of segments; 
 transmitting the plurality of segments in a single aggregated medium access control protocol data unit (A-MPDU) including medium access control protocol data units (MPDUs); 
 receiving a retransmission request from the transmitter, the retransmission request including a segment retransmission bitmap field indicating at least one segment of the plurality of segments for retransmission; and 
 in response to the retransmission request, transmitting second feedback data including the at least one segment indicated by the segment retransmission bitmap field. 
 
     
     
       2. The method of  claim 1 ,
 wherein each of the plurality of segments is identified by a first segment subfield and a remaining segment subfield, 
 wherein the first segment subfield indicates whether or not the corresponding segment is a first segment of the plurality of segments, and 
 wherein the remaining segment subfield indicates a number of remaining segments. 
 
     
     
       3. The method of  claim 2 , wherein the remaining segment subfield is set to 0 if the segment is a last segment. 
     
     
       4. The method of  claim 2 , wherein the first segment subfield is set to 1 if the segment is the first segment, and the first segment subfield is set to 0 if the segment is not the first segment. 
     
     
       5. A device configured to perform channel sounding in a wireless local area network, the device comprising:
 a transceiver; and 
 a controller operatively connected to the transceiver and configured to: 
 receive a null data packet announcement (NDPA) frame from a transmitter to initiate the channel sounding, 
 receive a null data packet (NDP) from the transmitter, the NDP following the NDPA frame, 
 configure a first report field including beamforming information and a second report field including signal to noise ratio (SNR) information, 
 split first feedback data including the first report field and the second report field into a plurality of segments, 
 transmit the plurality of segments in a single aggregated medium access control protocol data unit (A-MPDU) including medium access control protocol data units (MPDUs), 
 receive a retransmission request from the transmitter, the retransmission request including a segment retransmission bitmap field indicating at least one segment of the plurality of segments for retransmission, and 
 in response to the retransmission request, transmit second feedback data including the at least one segment indicated by the segment retransmission bitmap field. 
 
     
     
       6. The device of  claim 5 ,
 wherein each of the plurality of segments is identified by a first segment subfield and a remaining segment subfield, 
 wherein the first segment subfield indicates whether or not the corresponding segment is a first segment of the plurality of segments, and 
 wherein the remaining segment subfield indicates a number of remaining segments. 
 
     
     
       7. The device of  claim 6 , wherein the remaining segment subfield is set to 0 if the segment is a last segment. 
     
     
       8. The device of  claim 6 , wherein the first segment subfield is set to 1 if the segment is the first segment, and the first segment subfield is set to 0 if the segment is not the first segment. 
     
     
       9. A method for channel sounding in a wireless local area network, the method performed by a transceiver and comprising:
 transmitting a null data packet announcement (NDPA) frame to a receiver to initiate the channel sounding; 
 transmitting a null data packet (NDP) to the receiver, the NDP following the NDPA frame; and 
 receiving first feedback data in a plurality of segments in a single aggregated medium access control protocol data unit (A-MPDU) including medium access control protocol data units (MPDUs), 
 wherein the first feedback data includes a first report field including beamforming information and a second report field including signal to noise ratio (SNR) information; 
 transmitting a retransmission request to the receiver, the retransmission request including a segment retransmission bitmap field indicating at least one segment of the plurality of segments for retransmission; and 
 in response to the retransmission request, receiving second feedback data including the at least one segment indicated by the segment retransmission bitmap field. 
 
     
     
       10. The method of  claim 9 ,
 wherein each of the plurality of segments is identified by a first segment subfield and a remaining segment subfield, 
 wherein the first segment subfield indicates whether or not the corresponding segment is a first segment of the plurality of segments, and 
 wherein the remaining segment subfield indicates a number of remaining segments. 
 
     
     
       11. The method of  claim 10 , wherein the remaining segment subfield is set to 0 if the segment is a last segment. 
     
     
       12. The method of  claim 10 , wherein the first segment subfield is set to 1 if the segment is the first segment, and the first segment subfield is set to 0 if the segment is not the first segment. 
     
     
       13. A device configured to perform channel sounding in a wireless local area network, the device comprising:
 a transceiver; and 
 a controller operatively connected to the transceiver and configured to: 
 transmit a null data packet announcement (NDPA) frame to a receiver to initiate the channel sounding, 
 transmit a null data packet (NDP) to the receiver, the NDP following the NDPA frame, 
 receive first feedback data in a plurality of segments in a single aggregated medium access control protocol data unit (A-MPDU) including medium access control protocol data units (MPDUs), 
 wherein the first feedback data includes a first report field including beamforming information and a second report field including signal to noise ratio (SNR) information, 
 transmit a retransmission request to the receiver, the retransmission request including a segment retransmission bitmap field indicating at least one segment of the plurality of segments for retransmission, and 
 in response to the retransmission request, receive second feedback data including the at least one segment indicated by the segment retransmission bitmap field. 
 
     
     
       14. The device of  claim 13 ,
 wherein each of the plurality of segments is identified by a first segment subfield and a remaining segment subfield, 
 wherein the first segment subfield indicates whether or not the corresponding segment is a first segment of the plurality of segments, and 
 wherein the remaining segment subfield indicates a number of remaining segments. 
 
     
     
       15. The device of  claim 14 , wherein the remaining segment subfield is set to 0 if the segment is a last segment. 
     
     
       16. The device of  claim 14 , wherein the first segment subfield is set to 1 if the segment is the first segment, and the first segment subfield is set to 0 if the segment is not the first segment.