Abstract: A low complexity iterative receiver algorithm was proposed for high dimension modulation system. This algorithm consists of two steps: the first step is zero forcing multiuser detection (MUD) algorithm. The second is performed by a soft-input soft-output (SISO) multiuser detector and a bank of SISO channel decoders through an iterative process. The SISO multiuser detector adopts a novel soft interface cancellation method based on a linear minimum mean-squared error (LMMSE) filter. It makes the detector overcome the limitation of binary phase shift keying (BPSK) while the complexity is polynomial in terms of codes to be detected in the system. Simulation results show that, the performance of the proposed iterative receiver can approach that of a single code system with maximal likelihood detection (MLD) only after two iterations.

Key words: iterative multiuser detection, high order modulation, soft-input soft-output