Near Optimum Iterative Decoding of Block Codes in MIMO Systems

Near optimum iterative decoding of block codes in multiple input multiple output (MIMO) systems is proposed and analyzed applying a new suboptimal space time soft input soft output detector and Chase Pyndiah decoder for FEC detection. The suboptimal space time detector applies zero forcing detection to estimate the center and radius of the hyper-sphere which determines a subset of the most probable transmitted symbol vectors. The soft values are calculated considering only the symbol vectors in the subset, which reduces the computational complexity of the algorithm to 11% at high SNR compared to the standard soft information estimation. The computer simulations modeling IEEE 802.16 standard for broadband wireless access show, that the system performance is decreased less than 1dB compared to ML solution.