A low complexity receive space diversity architecture for broadband OFDM systems

Multiple receive antennas combined with orthogonal frequency division multiplexing (OFDM) can be used to significantly improve system capacity and performance in wireless systems. However, the complexity of such combination can be very large because one discrete Fourier transform (DFT) block for each receive antenna is required to fully take advantage of the space diversity. We present a low complexity receiver architecture for an OFDM system employing multiple receive antennas. It is shown that by exploiting the principle of orthogonal design, which has been successfully used to design space time block codes, one can reduce the number of DFT blocks without the space diversity order loss. Simulation results are provided to justify our analysis.