Impact of Noise Imbalance on the Performance of Predetection Dual-EGC Receivers Over Rayleigh Fading Channels

Abstract

A new expression for the probability density function of the signal-to-noise ratio (SNR) at the output of a predetection dual-equal-gain-combining (dual-EGC) receiver over independent but non-identical Rayleigh fading paths with different noise levels is derived. A closed-form expression for the average bit error rate (ABER) for coherent binary modulation schemes is also derived. The effect of the degree of noise imbalance on ABER is studied. From the results we determine the ranges of noise imbalance for a given average SNR per path over which the performance of predetection dual-EGC is better or worse than SC and single path receivers.