Optimization of effective data rate under rayleigh multipath fading in multimedia DS-CDMA systems

This paper studies the optimization of multimedia data under Rayleigh fading channels. We first review the results for Shannon capacity of fading channels with channel side information, where capacity is achieved by using an optimal power control scheme. Then an optimal SIR level γ*₀ is derived with the Lagrangian multiplier method. In this way, the interference is minimized and the effective data rate is maximized for the whole system. It is shown that γ*₀ is dependent on the interference level and outage probability of the system. Numerical results are provided which validates the theoretical deductions. We conclude that the total effective data rate will be maximized as long as the interference factor of power control is ρ<0.5 for a proper value of γ*₀.