A Power Control Based Admission Algorithm for Maximizing Throughput in a CDMA Network

In this paper we examine the aggregate throughput of the uplink of a circuit switched CDMA data transmission system using a combination of theoretical and simulation techniques. The theoretical analysis determines the transmitter power levels and the number of active terminals that jointly maximize the throughput via standard optimization methods. We find that the terminal with the lowest path gain should transmit at maximum power and that all other terminals should aim for a common received power level that is higher than the received power from the terminal with lowest path gain. In addition we show that the system should admit the number of terminals that results in a target signal-to-interference-plus-noise ratio that depends on the processing gain and the noise power. A numerical example suggests that power control designed to achieve equal received power for all terminals results in aggregate throughput nearly as high as that obtained with optimum power control. This finding greatly simplifies the engineering problem from a network manager's viewpoint.