On the Performance Analysis of Digital Modulations in Generalized-K Fading Channels

In this paper we present novel expressions for several performance metrics of communication systems operating over a composite fading environment modelled by the generalized-K distribution. Initially, for a generalized-K fading channel with arbitrary values for the small and large-scale fading parameters we derive a closed-form expression for the moment generating function (MGF) of the received signal-to-noise ratio (SNR) and utilize it to obtain the exact average symbol error probability for a variety of digital modulations using the MGF based approach. Then, for integer values of the small-scale fading parameter, we derive a novel closed-form expression for the cumulative distribution function of the received SNR, which is then used to obtain closed-form expressions for the outage probability, the average bit error probability of various digital modulations, and the ergodic capacity of the generalized-K fading channel.