The Impact of Adaptation Policies on Channel Capacity over Rayleigh Fading with Egc Diversity

In this paper, we study the basic diversity combining techniques and investigate analytically-derived closed-form expressions for the capacities per unit bandwidth for Rayleigh fading channels with equal gain combining (EGC) diversity. We consider different channel performance adaptation policies such as: power and rate adaptation with constant transmit power, channel inversion with fixed rate, and truncated channel inversion. A simulation of these schemes was carried out under ideal communication conditions and their performance compared. Results obtained show that channel inversion policies gave the highest capacity over other adaptation policies (with EGC diversity) while the constant transmit power policy yielded the lowest capacity. Furthermore, the truncated channel inversion policy outperformed other policies, while the constant power policy had the lowest capacity, compared to other policies.