Performance Analysis of an Integrated CS/PS Services CDMA System

An analytical model is developed to investigate integrated CS/PS CDMA cellular systems with SIR-based power control. Because packet data are not very sensitive to delay, a defer-first-transmission transmission mode is usually applied to packet data transmission. In the mixed CS/PS environment, link-level congestion control is designed to delay packet data, if necessary, to guarantee real-time delivery quality for CS traffic such as voice and CS data. In interference-limited CDMA cellular systems, because interference (both intracell and intercell) is the limit to spectral efficiency, congestion control is driven by the total received interference level at the BS. With congestion control at link level and SIR-based power control, the intracell and intercell interferences are closely related to each other. A recursive process is developed to evaluate the performance of such a CDMA system. Numerical results such as system capacity and data delay, both with and without power control error considered, are presented.