Efficient transmit diversity scheme for synchronisation channel in OFDM cellular systems

Two multiple antenna transmission schemes are considered for the synchronisation channel. One is a time switching transmit diversity (TSTD) and the other is a frequency switching transmit diversity (FSTD). It is shown through simulation results that the TSTD provides a beamforming gain as well as a diversity gain if it is based on a non-diagonal precoding matrix. Although the FSTD performs better than TSTD at a first detection trial in a high signal-to-noise ratio (SNR) case, the TSTD performs better than FSTD at all the other detection trials, which is due to beamforming gain. In addition, in an extremely low SNR case, the TSTD performs better than FSTD at all detection trials.