Soft-input soft-output decorrelating detectors for coded multiuser systems

In this correspondence, we propose a soft-input soft-output (SISO) decorrelating detector for iterative receivers of coded multiuser systems. Based on the soft inputs from a bank of single-user decoders, the cross-correlation matrix of multiple users is updated and employed in each iteration. Due to negligible residual interference and reduced noise enhancement in successive iterations, the resulting system performance quickly approaches to that of the single-user system. Furthermore, the detector is shown to have good near-far resistance. The computational complexity of the SISO decorrelator is proportional to the number of users cubed. Monte Carlo simulation results are provided and compared.