Throughput analysis of multirate VSG CDMA wireless packet communication systems in Rayleigh fading environment

This paper is concerned with packet error rate analysis for a multirate VSG CDMA wireless packet communication system. Based on the improved Gaussian approximation (IGA), we derive new expressions for the packet error probability that account for the different classes of users' rates in a Rayleigh fading environment. This is used to select the optimum users' power levels that maximise the overall average throughput of a network with dual classes. Our numerical results show that the optimum power of an m-rate user is not always m times greater than the power of the basic rate, as commonly assumed in the previous literature. In contrast, the optimum power, in addition to the rates of the different classes, also depends on the spreading gain and the number of instantaneous packets.