Optimization of non-binary LDPC coded massive MIMO systems with partial mapping and EP detection
Zhijie Feng, Qingqing Liu, Jin Xu, Weihua Liu, Zhe Zhang, Xueyan Chen, Hanging Ding · 2021
In this work, a non-binary low density parity check (LDPC) coded high dimensional multiple input multiple output (MIMO) scheme with partial mapping for high order modulation is proposed. For the proposed scheme, when$M$-ary quadrature amplitude modulation (QAM) is employed, then non-binary LDPC code constructed over Galois field with order$\sqrt{M}$is used for partial mapping, where$\sqrt{M}$is an integer. At the receiver side, a real-valued expectation propagation (REP) based detection algorithm is used. Furthermore, symbol-wise extrinsic information transfer (SEXIT) chart based iterative optimization algorithm is used to optimize the concatenated non-binary LDPC code. A simplified method is proposed to calculate the component EXIT chart of the massive MIMO detector, which can avoid a large amount of simulations. Numerical simulation results demonstrate the validity of the above idea.