An effective CIC (co-channel interference canceller) scheme for multi-rate CDMA

This paper proposes an improved CIC scheme for lessening noise enhancement extended from SD (soft decision)-based parallel cancellation. The scheme is effective especially in multi-rate CDMA. Its hardware is more complex than that of conventional SD-based CIC, but it is still less than that of the HD (hard decision)-based CIC with channel estimators. Because the processing delay is as small as that of the conventional SD-based CIC, TPC (transmission power control) can be performed immediately, based on the measured SIR after interference cancellation in the proposed CIC as well as in the conventional SD-based CIC. Our computer simulation shows that the capacity normalized by the processing gain is 0.50 without interference cancellation, 0.70 with conventional SD-based CIC, and 0.83 with the proposed CIC, at 8 dB of the required S/N for 0.1% BER by one CIC stage