An efficient space-frequency coded wideband OFDM system for wireless communications

A space-frequency coded OFDM system for high-speed transmission over wireless links is proposed in this paper. The analytical expression for the error event probability of such space-frequency coded OFDM system is derived in slow, spatial and frequency selective fading channels. The design criteria of TCM codes used in the proposed system are then developed and discussed. It is shown that the proposed space-frequency coded OFDM with low trellis complexity can efficiently exploit the available diversity resources of the fading channel, while in conventional space-frequency coded OFDM systems, space-time trellis codes with very high trellis complexity are required to make full use of the diversity resources. Simulation results show that at a FER of 10^-2, the proposed scheme outperforms the traditional space-frequency coded OFDM by 2 ∼ 4 dB at an equal trellis complexity and spectral efficiency