Exact Average Bit-Error Probability for Maximal Ratio Combining with Multiple Cochannel Interferers and Rayleigh Fading

An exact closed-form expression is derived for the average bit-error probability (BEP) of binary phase-shift keying signals with multiple-antenna reception. We consider maximal ratio combining technique in the presence of multiple cochannel interferers with identical or different powers and additive white Gaussian noise. It is assumed that both the desired signal and interference are subject to flat Rayleigh fading, and the fading channels of different users are independent of each other. In this paper, the derivation of the average BEP is different from the conventional PDF-based approach and is based on the decision variable at the output of the maximal ratio combiner conditioned only on the fading channel of the desired user. The analytical result is verified by Monte Carlo simulations.