ABER of Dual Predetection EGC in Correlated Nakagami-m Fading Channels with Arbitrary m

We have analyzed the performance of a predetection equal gain combining (EGC) receiver over correlated Nakagami-m fading channels with arbitrary and non-identical m and unequal branch SNRs. Closed-form expression for average bit error rate (ABER) for coherent binary modulation schemes is derived by finding the characteristic function (CHF) of the sum of two correlated Nakagami-m envelopes with different fading parameters and then using Parseval's theorem. The derived expression can be viewed as a generalization of four different special cases reported in the literature. It was observed that depending on the values of m1 and m2 the ABER curves for two different pairs of (m1,m2) may intersect. Thus, if the performance corresponding to a pair is inferior to another pair at any SNR, this may not hold true over the entire SNR range.