Abstract: A data feedback method includes acquiring, by the beamformee, the number of columns from a null data packet announcement (NDPA) message; detecting the number of active first spatial streams; comparing the number of first spatial streams with the number of columns, and taking the smaller value obtained from the comparison as the number of second spatial streams required for feedback; and feeding back the number of second spatial streams and spatial stream measurement information about the second spatial streams to the beamformer.

Abstract: A data feedback method includes acquiring, by the beamformee, the number of columns from a null data packet announcement (NDPA) message; detecting the number of active first spatial streams; comparing the number of first spatial streams with the number of columns, and taking the smaller value obtained from the comparison as the number of second spatial streams required for feedback; and feeding back the number of second spatial streams and spatial stream measurement information about the second spatial streams to the beamformer.

Abstract: Embodiments of the present invention disclose a method and an apparatus for retrieving transmission opportunity control in reverse direction grant. The method includes: obtaining, by a reverse direction responder (RD responder), a TXOP control from a reverse direction initiator (RD initiator); enabling, by the RD responder, a multi-user multiple-input multiple-output (MU-MIMO) mode; sending, by the RD responder, a frame to a plurality of stations concurrently in a TXOP period, the plurality of stations comprise the RD initiator; wherein the frame carries information that only requires the RD initiator to send back only a single acknowledgement in the TXOP period to return the TXOP control.

Abstract: Embodiments of the present invention disclose a method and an apparatus for retrieving transmission opportunity control in reverse direction grant. The method includes: obtaining, by a reverse direction responder (RD responder), a TXOP control from a reverse direction initiator (RD initiator); enabling, by the RD responder, a multi-user multiple-input multiple-output (MU-MIMO) mode; sending, by the RD responder, a frame to a plurality of stations concurrently in a TXOP period, the plurality of stations comprise the RD initiator; wherein the frame carries information that only requires the RD initiator to send back only a single acknowledgement in the TXOP period to return the TXOP control.

Abstract: Embodiments of the present invention disclose a method and an apparatus for retrieving transmit opportunity control in reverse direction grant, so that a conflict occurring between a case where an RD Initiator continues sending another frame to an RD Responder after retrieving TXOP control and a case where a terminal other than the RD Initiator sends a block acknowledgement to the RD Responder can be avoided. The method provided in the embodiments of the present invention includes: when an RD Initiator fails to correctly demodulate a frame sent by an RD Responder, retrieving, by the RD Initiator, TXOP control by using a PIFS if it is impossible for the RD Responder to enable an MU-MIMO mode, and retrieving, by the RD Initiator, the TXOP control by using a duration if it is possible for the RD Responder to enable the MU-MIMO mode, where the duration is longer than the PIFS.

Abstract: Provided in the embodiments of the present invention are a method, a device and a system for setting a weight feedback granularity, relating to communication technologies, which solve the problem that a beamforming transmitting end can not control a beamforming weight feedback granularity. The method comprises: receiving a null data packet announcement (NDPA) frame comprising a weight feedback granularity requirement value transmitted by the beamforming transmitting end; receiving a null data packet (NDP) frame transmitted by the beamforming transmitting end, and measuring the beamforming weight by using the weight feedback granularity requirement value as a granularity; and transmitting a very high throughput compressed beamforming (VCBF) frame to the beamforming transmitting end, wherein the very high throughput compressed beamforming (VCBF) frame comprises the beamforming weight using the weight feedback granularity requirement value as the granularity.

Abstract: A data feedback method includes acquiring, by the beamformee, the number of columns from the NDPA message; detecting the number of active first spatial streams; comparing the number of first spatial streams with the number of columns, and taking the smaller value obtained from the comparison as the number of second spatial streams required for feedback; and feeding back the number of second spatial streams and spatial stream measurement information about the second spatial streams to the beamformer.