Probability of Error Analysis of OFDM Systems with Random Residual Frequency Offset

In this paper, we derive closed form bit error rate (BER) expressions for orthogonal frequency division multiplexing (OFDM) systems with residual carrier frequency offset (CFO). Several papers have been written treating CFO as a nonrandom parameter where as we consider it as a random variable in this study. The BER performance of binary phase shift keying (BPSK) OFDM system is analyzed in the cases of additive white Gaussian noise (AWGN), frequency flat and frequency selective channels. We further derive an expression for the BER in flat fading Rayleigh channels without the perfect channel state information (CSI) at the receiver. The simulation results are provided to verify the accuracy of the new BER expressions.