Investigation of an enhanced nonlinear SIC receiver for the IS-95 downlink

Several techniques have been introduced to enhance the signal-to-interference-plus-noise ratio (SINR) of the nonlinear successive interference canceler (SIC). Some of these improvements are specific to the downlink (base station to mobile) of Interim Standard 95 (IS-95) for code-division multiple-access (CDMA) cellular systems. We extend this previous work by investigating how inclusion of these enhancements affects the probability of error for a weaker base station being demodulated. In addition to evaluating how SINR enhancement removes additional interference from stronger base station signals, we also discuss a joint detector designed to mitigate the interference of weaker base station signals. By using this joint approach, near-far effects can be reduced further for certain channels in the primary base station. Computer simulations are presented to verify the SINR model and demonstrate the performance gains.