Methods for monitoring channel sounding quality in WLAN devices

A wireless device, comprising:

• a receiving antenna that receives 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;
• a channel estimation module that performs channel estimation thereby determining an estimated channel matrix;
• a sounding quality calculation module that calculates channel quality by computing an estimation error of the received sounding signal based on the estimated channel matrix for each valid sub-channel;
• and
• a transmitter that transmits a feedback message to the access point, wherein the feedback message contains sounding quality information derived from the calculated sounding quality for each valid sub-channel, 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.

A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform a method, the 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.