MRC diversity for binary signals in correlated Nakagami fading

Abstract

The performance of maximal ratio combiner (MRC) diversity reception with L correlated branches in Nakagami fading is presented. Bit error rate (BER) is evaluated for binary signals starting from the L-variate moment-generating function (MGF) of the random input power vector. In the case of Nakagami fading the L-variate statistics are not uniquely determined by marginal distributions and covariance matrix; in particular, two different joint MGFs are presented for the L-variate Nakagami vector, which give the same marginal density functions and covariance matrix and are easily generated. The two MGFs yield two different closed form expressions for the BER of the MRC diversity with generic branch correlation. The sensible difference in performances suggests that marginal probability density functions (pdfs) and power covariance matrix are not sufficient to completely characterize correlated Nakagami fading.