Comparative performance of adaptive receivers for demodulating IS-95 downlink data

The performance of adaptive receiver architectures is investigated for demodulating IS-95 downlink data. The implementations include an adaptive minimum mean-square-error (MMSE) equalizer followed by a despreader, and an adaptive successive interference canceler (SIC), which are compared to a conventional matched filter (MF). By concentrating on an actual signal model (IS-95) and multipath channels, we address technical issues that other structures might not emphasize for generic CDMA (code-division multiple-access) signals. For the SIC, we are concerned with estimating the multipath channel as well as the relative user amplitude levels in order to regenerate a portion of the received signal due to a particular base station. Significant performance gains can be achieved by accurately identifying and equalizing for a base station channel using the pilot channel of the IS-95 downlink signal.