BER performance of OFDM system over frequency nonselective fast Ricean fading channels

The fast changing frequency nonselective Ricean fading channel introduces a complicated multiple distortion and an extra additive noise component for an OFDM system. The multiple distortion is the average of the sum of N(N/spl ges/3) correlated Ricean random variables. We propose an approximate technique for calculating the probability density function (PDF) of the multiple distortion under the assumption that the channel response changes in a linear fashion during one OFDM symbol. As a result, the bit error rate (BER) formula of a BPSK modulated OFDM system is derived. The results obtained using the derived formula describe well the OFDM performance under the time variant channel and match very well with the simulation results.