Optimal Combining with Arbitrary Power Interferers and Thermal Noise on Rayleigh Fading Channels

The performance of optimum combining is studied in a Rayleigh fading environment with arbitrary-power cochannel interferers and thermal noise. Based on the joint eigenvalue distributions of quadratic forms in complex Gaussian matrices, closed form expressions for exact moment generating function (MGF) of the output signal-to-interference-plus-noise ratio are derived. From the exact MGF, the moments of the output SINR and the symbol error rate of various M-ary moulation schemes are obtained. We verify the accuracy of our analytical results by numerical examples. The new analytical framework provides a simple and accurate way to assess the effects of equal and unequal-power cochannel interferers and thermal noise on the performance of optimum combining.