Linear detection in iterative joint multiuser decoding

In this paper we provide a tutorial-style overview of linear detection in iterative joint multiuser decoding. We show that a generic linear iterative joint multiuser decoder naturally replaces the canonical iterative joint multiuser decoder. The generic linear structure is particularly well-suited for interference cancellation and LMMSE filtering with priors, which incidently is interference cancellation followed by per-user instantaneous LMMSE filtering. A controversial issue for linear iterative joint multiuser decoding is the type of information feedback to the multiuser detector. Here we present numerical results for both the exchange of extrinsic and posterior information and conclude that in terms of spectral efficiency there are only small differences.