Map Demodulator for Time-selective Fading Cdma Channels

A decision-feedback MAP receiver for time-selective fading CDMA channels is proposed. The receiver consists of a sequence-matched jilter and a MAP demodulator Output samples from the matched~lter are fed into the MAP demodulator The MAP demodulator exploits the channel memory by delaying the decision and using a sequence of observations. This receiver also rejects MAI and estimates channel fading coej’icients implicitly to give good demodulation decisions. Moreovec computer simulations are perj$ormed to evaluate the BER pe~ormance of the receiver under various channel conditions.