Performance Analysis and Comparison of Dual-hop Amplify-and-forward Relaying over Mixture Gamma and Generalized-K Fading Channels

In this paper, we present the end-to-end performance of a dual-hop amplify-and-forward relaying system over Nakagami-lognormal (NL) fading channels by using mixture gamma (MG) distribution and Generalized-K (KG) distribution, respectively. Novel closed-form expressions for the probability density function, the cumulative distribution function and the moment-generation function of the end-to-end signal-to-noise ratio for dual-hop system are derived. Moreover, the average symbol error rate and outage probability are found based on the above new expressions, respectively. By using MG distribution, some exact closed-form expressions can be obtained, however, only some approximate expressions are obtained by using KG distribution. Finally, numerical and simulation results are shown to verify the accuracy of the analytical results. These results show that it is more precise and amenable to approximate the composite NL distribution by using the MG than the KG distribution in the performance analysis of cooperative systems.