Investigation of Switch and Stay Combiner performance over ‘independent’ and ‘i.i.d.’ K fading channels

The performance of Switch and Stay Combiner (SSC) over `independent´ and `independent and identically distributed´ (i.i.d.) K fading channels is analyzed and evaluated in this paper. The K distribution used to model composite fading channels can be obtained by averaging the conditional Rayleigh Probability Density Function (PDF) over the Gamma PDF. Expressions for the outage probability, moments of the output signal and the average bit error probability for noncoherent modulation schemes of the dual branch SSC receiver are derived in terms of the Meijer´s G-function. The analysis of optimum switching threshold is also carried out. The proposed mathematical analysis is accompanied with various numerical evaluation results to demonstrate and study the effect of different system parameters such as fading parameter, input average SNR, switching threshold SNR and modulation schemes on the performance of the receiver.