Performance evaluation of a composite microscopic plus macroscopic diversity system

Closed-form analytical solutions are obtained for the performance of M-branch maximal-ratio and selection microscopic diversity systems with a class of continuous phase and constant amplitude modulation schemes for Rayleigh and log-normal fading. The results indicate that diversity improvement is related to the standard deviation of the log-normal component and the improvement decreases as the standard deviation increases. Since microscopic diversity only mitigates the effect of fast (Rayleigh) fading, other means are needed to mitigate the effect of the slow (log-normal) component. A composite microscopic plus macroscopic diversity system was found to substantially improve the performance. Analytical results are produced for two-branch microscopic selection or maximal-ratio plus N-branch macroscopic selection diversity systems.<>