Performance of diversity schemes for OFDM systems with frequency offset, phase noise and channel estimation errors

We provide expressions for the bit error rate of various transmit and receive diversity schemes for orthogonal frequency-division multiplexing (OFDM) systems in the presence of frequency offset, phase noise and channel estimation errors. The derivations are also applicable for a general multiplicative distortion of the received signal. We compare two transmit diversity schemes (space-time and space-frequency diversity) with maximal ratio combining (MRC) receive diversity for frequency-selective Rayleigh fading channels. Our results show that with perfect channel estimates, practical values of the phase noise do not significantly degrade the performance of the various diversity methods for BPSK modulation. In contrast, the transmit diversity schemes for OFDM are much more sensitive to channel estimation errors than MRC receive diversity.