On the performance of fast forward link power control in IS-2000 CDMA networks

The quality of fast forward link power control in IS-2000 CDMA systems is examined by comparing it to ideal power control, for a one-path Rayleigh channel model. Closed form expressions are derived that relate average transmitted power and average received signal-to-noise ratio for ideal power control. Simulations are used to compare the power control achievable in a Radio Configuration 3 (RC3) IS-2000 system with that of ideal power control, for the case of a slowly moving (3 kmm) mobile. In this case, IS-2000 power control requires 4 dB more power than ideal power control for 1% frame error rate (FER), and 1.3 dB for an FER of 10%. The narrow margin for improvement at large FER targets makes it unlikely that substantial capacity gain can be achieved from improved power control in networks carrying mostly data traffic, since FER targets are likely to be higher for data than for voice.