Channel capacity per user in a power and rate adaptive hybrid DS/FFH‐CDMA cellular system over Rayleigh fading channels

The theoretically achievable average channel capacity (in the Shannon sense) per user of a hybrid cellular direct sequence/fast frequency hopping code‐division multiple‐access (DS/FFH‐CDMA) system, operating in a Rayleigh fading environment, was examined. The analysis covers the downlink transmission and leads to the derivation of a novel expression between the average channel capacity available to each system's user under simultaneous optimal power and rate adaptation and the system's parameters, providing an optimistic upper bound, useful for practical modulation and coding schemes. The final derived closed‐form expression can be useful for the design of the DS/FFH‐CDMA system because it provides a theoretical tool for the initial quantitative analysis. Finally, avoiding the application of complex theoretical algorithm or lengthy simulation, we theoretically derived numerical results to illustrate the presented analysis. Copyright © 2011 John Wiley & Sons, Ltd.