SER for Optimal Combining in Rician Fading with Co-channel Interference

Approximate Symbol error rate (SER) expressions are derived for receive diversity system employing optimum combining, when both the desired and the interfering signals are subjected to Rician fading, for the case of a) equal power uncorrelated interferers b) unequal power interferers c) interferer correlation. The derived expressions are applicable for an arbitrary number of receive antennas and interferers and for any QAM constellation. Furthermore, we derive a simple closed form expression for SER in the interference-limited regime, for the special case of Rayleigh faded interferers. A close match is observed between the SER result obtained through the derived analytical expression and the one obtained from Monte-Carlo simulations, for a variety of QAM constellations. Index Terms Optimum combining, Rician fading, SER, QAM, Wishart matrices, Hypergeometric functions