Turbo equalization of precoded collaborative MIMO for the uplink of LTE-advanced

We focus on turbo equalization receivers for frequency precoded Collaborative Spatial Multiplexing (CSM) MIMO in of the uplink of LTE-advanced system. In CSM, two or more users, equipped with multiple transmit antennas transmit their data within the same frequency/time grid. This scheme increases user capacity while providing antenna diversity. We propose a Space Frequency Block Coded (SFBC) (actually Precoded) CSM that doesn´t need CSI and derive a novel MMSE receiver in highly selective channels. Also, we propose a combined CSM and spatially precoded MIMO system with unlimited or limited feedback codebook based system. The paper continues with proposing soft parallel interference cancellation turbo equalization (PI C-TEQ) receiver for the presented precoded schemes in addition to novel initial guess ML add-on for PIC-TEQ. Simulation results show that the TEQ for precoded CSM provides tremendous enhancement in the performance and spectral efficiency of the uplink of the LTE system.