On the Optimum Power Allocation in a Cellular DS/FFH-CDMA System

The optimization between the average received power and the theoretically achievable average channel capacity per user (in the Shannon sense) of a hybrid direct-sequence/fast frequency hopping codedivision multiple-access (DS/FFH-CDMA) cellular system, when operating in a Rayleigh fading environment, is presented. The analysis leads to a novel-closed form expression for the optimal average received power value based on the maximization of the achieved spectral efficiency, estimated in terms of the available average channel capacity per user. Finally, respective numerical results are presented. Key-Words: Hybrid CDMA systems, Cellular systems, Channel capacity, Rayleigh fading.