Patent ID: 8804559
Filing Date: 2014-08-12
Classification: H04L,H04W

Abstract:
1. A method comprising: (a) receiving a sounding signal transmitted from an access point over a wide channel in a wireless network, wherein the sounding signal is transmitted over one or multiple sub-channels of the wide channel, wherein each sub-channel comprises a plurality of subcarriers; (b) performing channel estimation by a receiver thereby determining an estimated channel matrix; (c) calculating sounding quality by computing an estimation error of the received sounding signal based on the estimated channel matrix for each valid sub-channel; and (d) transmitting a feedback message to the access point, wherein the feedback message contains sounding quality information derived from the sounding quality calculated in (c), and wherein a null channel feedback frame is contained in the feedback message if the calculated sounding quality for each valid sub-channel is below a threshold indicating poor channel estimation quality.