QAM Symbol Error Rate in OFDM Systems Over Frequency-Selective Fast Ricean-Fading Channels

For digital data transmission using an orthogonal frequency-division multiplexing (OFDM) over fading channels, the interchannel- interference (ICI) term caused by the Doppler spread is correlated with the desired signal term. Nonetheless, many researchers have assumed the ICI term to be uncorrelated with the desired signal term. In this paper, we present the symbol-error-rate (SER) performance for the M-quadratic amplitude-modulation OFDM systems over Ricean fading using the exact correlated ICI model. The results are then compared with the uncorrelated ICI results. We find that the two results present some differences. The differences tend to increase as the Ricean factor is increased.