Beamforming in combination with space-time diversity for broadband OFDM systems

We investigate broadband OFDM systems which apply beamforming in combination with different space-time diversity techniques. Various beamforming scenarios with transmitter and/or receiver sided beamforming are considered. Space-time diversity is obtained by cyclic delay diversity (CDD) in order to artificially shape the spectrum of the received signal. Thus, an advantageous distribution of the errors before a Viterbi channel decoder is obtained. Simulation results for the bit error rate performance are presented and compared for OFDM systems applying different beamforming scenarios and CDD in a Rayleigh fading channel. Maximum ratio combining (MRC) of the signals received on multiple beams/antennas is also taken into account in the performance analysis