Performance evaluation of power control bit detection for an adaptive SIC receiver and the IS-95 downlink

In adaptive successive interference cancellation (ASIC), a code-division multiple-access (CDMA) receiver attempts to reconstruct and cancel strong base station signals for which the long spreading codes may not be known. One technique that can lead to more accurate base station signal reconstruction locates the power control bits (PCB) within a power control group (PCG) and scales the signal amplitude according to the rate being used for a particular Walsh channel. In this paper, we investigate the performance of this technique by determining under what conditions PCB detection provides improved signal cancellation. Based on an average interference criterion, the probability of correctly determining the PCB locations are derived for the downlink specified in Interim Standard 95 (IS-95). Computer simulations are presented to verify the analytical results.