SIGNAL AND INTERFERENCE STATISTICS OF A CDMA SYSTEM WITH FEEDBACK POWER-CONTROL .2.

Power control is essential in the use of direct-sequence code-division multiple-access (CDMA) techniques. Early system-level performance ana lyses of a CDMA approach to wireless mobile and personal communication s have assumed the ability of power control to equalize the absolute s ignal powers of CDMA users received at each base station. This paper s tudies a more practical, although analytically more complicated, uplin k power control technique that uses measurements of the received signa l-to-interference ratio (SIR) instead. A combination of discrete-event link simulation and analysis of the obtained SIR statistics is used t o explore the previously little-known behavior of a CDMA system using SIR-based power control and to obtain performance estimates for such a system under various operating assumptions. The overall results indic ate that power control based on SIR has the potential for somewhat hig her system performance than power control based on absolute signal str ength assumed in the early analyses.