Iterative Successive Interference Cancellation Based on Multiple Feedback For Multiuser MIMO Systems

In this paper, a new low-complexity multiple feedback successive interference cancellation (MF-SIC) strategy is proposed for the uplink of multiuser multiple-input multiple-output (MU-MIMO) systems. In the proposed MF-SIC with shadow area constraints (SAC) algorithm, an enhanced multiple user interference (MUI) cancellation is achieved by introducing the feedback diversity (FD) to combat the error propagation in decision feedback loops. We also combine the MF-SIC with multi-branch (MB) processing, which achieves a higher detection diversity. For coded systems, a low-complexity soft-input soft-output (SISO) iterative (turbo) detector is proposed based on the MF interference suppression and the soft canceler followed by a MMSE scheme (SC/MMSE). The computational complexity of the proposed MF-SIC is as low as the conventional SIC algorithm with very low additional complexity added. The simulation results show that the algorithm significantly outperforms the conventional SIC schemes and approaches the single user bound performance in coded systems.