Adaptive multiuser parallel-decision-feedback with iterative decoding
Michael L. Honig, Graeme Woodward, Paul D. Alexander · 2002
We combine the adaptive (least squares) parallel-multiuser decision feedback detector for CDMA with short spreading sequences, presented by Ratasuk et al. (see In Proc. Allerton Conf., Monticello, IL, 1999), with iterative (turbo) decoding and soft cancellation, presented by Alexander et al. (see European Trans. on Telecomm., vol.9, no.5, p.419-25, 1998). The resulting receiver requires only a training sequence and (coarse) timing for estimation of all filter coefficients, and performs close to the single-user bound with relatively low E/sub b//N/sub 0/. Prior knowledge of spreading codes and channels is unnecessary. For simplicity, we consider a synchronous CDMA system.