Patent ID: 8160188
Filing Date: 2012-04-17
Classification: H04L

Abstract:
1. A method for maintaining channel reciprocity at a time-division duplex (TDD) Orthogonal Frequency Division Multiplexing (OFDM) transceiver, the method comprising: receiving a first receive-signal using a first antenna and a second receive-signal using a second antenna, wherein the first receive-signal and the second receive-signal correspond to a first OFDM signal; transforming the first receive-signal into a first frequency domain receive-signal representing amplitudes and phases of first sub-carriers; transforming the second receive-signal into a second frequency domain receive-signal representing amplitudes and phases of second sub-carriers; applying a cyclic delay to one of the first sub-carriers in the first frequency domain receive-signal to generate a cyclically delayed first frequency domain receive-signal; and combining the second frequency domain receive-signal with the cyclically delayed first frequency domain receive-signal, wherein the cyclic delay is applied to a signal sent from the first antenna.