基于定型匹配成形的 5G LDPC 编码调制方案

Constellation shaping, one of the key techniques for the communication systems, can provide shaping gain. However, recently proposed constant composition distribution matching (CCDM) probabilistic amplitude shaping (PAS) scheme is only suitable for square constellation modulation but not for general structured 2D constellation. This paper presents a generalized CCDM shaping, which can be directly applied to any 2D constellation with a symmetric structure. Furthermore, taking into account the 5G low-density parity-check (LDPC) standard (especially for the puncture structure), the presented CCDM shaping is combined with the 5G LDPC codes, resulting in a 5G LDPC coded shaping modulation scheme. The numerical results show that the performance of the proposed scheme is consistent with that of the conventional PAS scheme. The simulation results also show that the proposed 5G LDPC coded shaping modulation scheme can achieve a shaping gain of about 0.6 dB and a puncturing gain of about 0.5 dB (compared with the non-puncturing design).