Effect of Mobility on Power Control and System Capacity in CDMA Cellular Wireless Networks

We consider a CDMA cellular wireless access network that handles various classes of calls that are characterised by different bit rates and Eb=N0 requirements. For the uplink of such a system we study the relationship between power control, admission control and user mobility. We compare two methods for power control: Constant Received Power Control (CRPC) in which the total power received at each base station (BS) is kept constant, and each Mobile Station (MS) is assigned a fraction of this received power, and Constant Signal to Interference Ratio (SIR) Power Control (CSPC) in which each MS is dynamically power controlled such that the measured SIR at the Base Station is kept constant. In steady state, for stationary mobiles, CSPC should provide a larger admission region than CRPC. We calculate the admission regions for CRPC and CSPC under various mobility conditions, and find that with high mobility CRPC outperforms the CSPC based algorithm.