Patent ID: 7778607

Claim:
A method of estimating a communication channel comprising one or more sub-channels between at least a first transceiver and at least a second transceiver, the method comprising: (a) transmitting a first set of training data from the first transceiver to the second transceiver; (b) receiving first observed signals resulting from the transmitted first set of training data at the second transceiver, and re-transmitting said first observed signals to the first transceiver, wherein said first observed signals contain data representative of symbols contained in the first set of training data; (c) receiving the re-transmitted first observed signals at the first transceiver, and calculating a roundtrip channel estimate at the first transceiver; (d) transmitting a second set of training data from the second transceiver to the first transceiver; (e) receiving second observed signals from the transmitted second set of training data at the first transceiver, and calculating a reverse channel estimate at the first transceiver based on the received second observed signals; and (f) calculating a forward channel estimate at the first transceiver based on the calculated round-trip channel estimate and the calculated reverse channel estimate; wherein the round-trip channel estimate is representative of channel conditions of a round-trip communication channel including a forward communication channel from the first transceiver to the second transceiver and a reverse communication channel from the second transceiver to the first transceiver.