Non-binary LDPC Coded Orthogonal Modulation with Non-coherent Detection

Abstract

A symbol-level iterative decoding scheme of non-binary LDPC coded orthogonal modulation with non-coherent demodulation is presented. Compared to the conventionally used bit interleaved coded modulation with iterative decoding (BICM-ID), the proposed scheme directly combine LDPC codes over GF(q) (q>;2) with M-ary orthogonal modulation together. The soft input and soft output demodulation with non-coherent detection is discussed to obtain the symbol level soft decision information to initialized the iterative decoding process of non-binary LDPC codes. Simulation-oriented method is employed to find optimal LDPC codes of a certain kind. Results indicate our proposed scheme owns a better performance than BICM-ID and lower computational complexity to achieve a soft input and soft output demodulation.