Patent ID: 8295384

Claim:
A method comprising: receiving transmissions at a plurality of antennas of a first wireless communication device sent from a plurality of antennas of a second wireless communication device; generating for received transmissions channel estimate information for a wireless channel between the plurality of antennas of the first wireless communication device and the plurality of antennas of the second wireless communication device; estimating a number of spatial streams for received transmissions based on transmit rate information contained in the received transmissions; evaluating the estimated number of spatial streams for received transmissions with respect to a number of antennas at the second wireless communication device to determine when sufficient information is available to estimate a spatial expansion matrix used by the second wireless communication device when sending to the first wireless communication device transmissions comprising a number of spatial streams less than the number of antennas of the second wireless communication device; and when it is determined that sufficient information is available, generating an estimate of the spatial expansion matrix from the channel estimate information for a received transmission determined to have been sent with a number of spatial streams less than the number of antennas of the second wireless communication device and from the channel estimate information for a received transmission determined to have been sent without spatial expansion.