Parallel interference cancellation based turbo space-time equalization in the SDMA uplink

A novel parallel interference cancellation (PIC) based turbo space time equalizer (STE) structure designed for multiple antenna assisted uplink receivers is introduced. The proposed receiver structure allows the employment of non-linear type of detectors such as the Bayesian decision feedback (DF) assisted turbo STE or the maximum aposteriori (MAP) STE, while operating at a moderate computational cost. Receivers based on the proposed structure outperform the linear turbo detector benchmarker based on the minimum mean-squared error (MMSE) criterion, even if the latter aims for jointly detecting all transmitters´ signals. Additionally the PIC based receiver is capable of equalizing non-linear binary pre-coded channels. The performance difference between the presented algorithms is discussed using extrinsic information transfer-function (EXIT) charts