Average error rate of linear diversity reception schemes over generalized gamma fading channels

We study the performance of M-ary modulation schemes in the presence of additive white Gaussian noise (AWGN) and slow fading. Selection combining (SC), equal gain combining (EGC), and maximal ratio combining (MRC) diversity schemes are considered. The fading channel is modeled by the generalized gamma distribution, which includes the Rayleigh, Nakagami, Weibull, and log-normal distributions as special or limiting cases. The Suzuki distribution can be adequately approximated by the generalized gamma distribution. The exact average symbol error rates (ASER) for coherent multilevel modulation schemes with SC and MRC are presented by using the moment generating function (MGF) based approach while that of EGC is obtained by employing a characteristic function (CHF) based approach. The analysis results for the three combiners are compared and discussed. Simulation results are also provided.