Approximate BER performance of generalized selection combining in Nakagami-m fading

Abstract

The error performance of generalized selection combining (GSC), which optimally combines the K highest signal-to-noise ratio (SNR) signals out of L total diversity signals, in Nakagami-m fading was recently evaluated using moment generating function (MGF) of the GSC output SNR. However, no single closed-form expression for the MGF exists for arbitrary K and L. In fact, closed-form expression for the MGF is possible only for individual combination of K and L. In this letter, a single closed-form expression for approximating the MGF is, therefore, derived and employed in evaluating the approximate error performance. Although the approximation is only applicable for GSC with K being a factor of L, it nonetheless achieves a high degree of accuracy.