Power imbalance effects on packet CDMA

This paper presents an analysis of packet code-division multiple-access (CDMA) with single user receivers and power level variations. The power level variations are due to imperfect power control. The teletraffic is modeled as an M/G/∞ queueing system. Average error rates and outage probabilities that a user sees are evaluated for a single cell CDMA system. The effects of power level variations are investigated using a combination of an approximation and an upper bound, and the loss in traffic capacity is evaluated. Numerical results for CDMA systems with different processing gains and coding gains are presented. It is shown that imperfect power control reduces significantly the CDMA teletraffic capacity, and much has to be gained by improving the power control schemes. The methods and results of this work could be used for quantifying the required accuracy of power control in CDMA and for evaluation of the capacity loss due to power control errors