Log-likelihood-ratio ordered successive interference cancellation in multi-user, multi-mode MIMO systems

Log-likelihood-ratio (LLR) ordered successive interference cancellation (SIC) scheme is analyzed in multi-user, multi-mode, multi-input multi-output (MIMO) systems in which each user may choose between two operation modes: spatial multiplexing or beamforming. The main idea is to detect and cancel the user signal in order of LLR which provides a posteriori information about the reliability of detection. The simulation results indicate that LLR-ordered SIC provides 1 ~ 3 dB gain over the conventional SNR-ordered SIC in multiuser MIMO system and the gain increases with increasing number of users.