Iterative EP Detection and Decoding of Polar-Coded MIMO Systems

Channel coding and multiple-input multiple-output (MIMO) antennas are two key technologies in the modern communication system. For MIMO detection, the expectation propagation (EP) detector has been proved to outperform classical and advanced solutions. Merging with the parity constraints of channel coding, a novel EP detection with linear programming (LP), named EPLP, is proposed to change the common initialization that the symbols are equiprobable by formulating an LP optimization problem. Furthermore, we apply the EPLP detector to a polar-coded MIMO system with an iterative detection and decoding (IDD) scheme. For a (128, 64) polar-coded 16 x 16 QPSK configuration, the EPLP outperforms the state-of-the-art detectors by 1 dB at the bit error rate of 10(-3) and the IDD scheme with the EPLP achieves 0.5 dB gain at the frame error rate of 10(-5) with a reduced number of EP iterations.