Approximation techniques for analytical characterization of downlink traffic power for multi-service CDMA networks

This paper presents a novel analytical framework for characterizing the downlink power allocations for a multi-rate Code Division Multiple Access (CDMA) network. The characterization takes into account the RF propagation model, the shadowing process and considers both intracell and intercell interference. To arrive at the model, the paper utilizes approximation techniques recently developed in the recent literature to evaluate the sum of lognormal random variables. The overall traffic power is modeled as a random variable that is function of the network parameters and the assigned downlink bit rates. The paper demonstrates the calculation of the forward link power outage probability as one example application for the developed characterization. It also compares between two approximation techniques suggested in this paper: matched first and second order statistics, and the min-max technique. The analytical results are compared to those obtained via Monte-Carlo simulations to assess the accuracy of the adapted approximations. The results indicate the min-max technique produces more accurate results when compared to matched first and second moments approximation scheme.