Asynchronous multiuser CDMA detector made simpler: novel decorrelator, combiner, canceller, combiner (DC3) structure

A code division multiple access (CDMA) detector that employs a combination of a decorrelator and an adaptive interference canceller was proposed by Siveski, Bar-Ness and Chen (1994) for the synchronous channel. For the asynchronous channel, the one-shot approach was suggested. It requires a (2K-1) dimensional decorrelator and a canceller (K is the number of users) and must be repeated once for every user if adequate performance for all users is sought. Instead, we propose in this paper a decorrelator, data combiner, canceller, data combiner arrangement. Using maximum signal-to-noise ratio (SNR) combining at both data combining stages, we show that the resulting decorrelator canceller performs with an asynchronous channel as does that for the synchronous case