一种用于BICM-ID系统的新颖8APSK映射方案

A Novel Mapping Scheme of 8APSK Modulation for BICM-ID Systems

为了能够通过高阶调制信号增加信道容量,提高编码增益和频谱效率,对8阶振幅移相键控(APSK)星座映射方案进行优化。基于欧氏距离设计准则提出一种新颖(2,6)-scheme 8APSK映射方案,并应用于联合准循环构造法构造的低密度奇偶校验(LDPC)(4 599,4 307)码的比特交织编码调制迭代译码(BICM-ID)系统中。信道容量仿真表明,所提方案在高、低信噪比区域都具有非常优越的互信息性能。误码率(BER)性能仿真表明,在BER为10-7时,联合LDPC(4 599,4 307)码的(2,6)-scheme 8APSK映射方案较(4,4)-scheme 8APSK映射方案、8PSK调制的格雷(Gray)映射、集分割(SP)映射、半集分割(SSP)映射分别提高了约0.45 d B、1.10 d B、1.62 d B、2.13 d B的编码增益。外附信息转移(EXIT)图仿真说明,所提方案能够更早地打开译码通道,从而更早地通过迭代来实现无错译码。

In order to increase the channel capacity and improve the coding gain（ CG） and spectral efficiency through the high order modulation signal,the 8APSK constellation mapping scheme is optimized. A novel（2, 6） -scheme 8APSK mapping scheme based on the Euclidean distance design criterion is proposed and ap-plied to the bit-interleaved coded modulation with iterative decoding（BICM-ID） systems,which combines LDPC（4599,4307） codes constructed by the quasi-cyclic（ QC） method. The channel capacity simulation result shows that the new scheme has excellent mutual information performance in the high and low signal-to-noise ratio（SNR） regions. The bit error rate（BER） performance simulation indicates that the CG of new scheme joining the LDPC（4599,4307） code has improved 0. 45 dB、1. 10 dB、1. 62 dB、2. 13 dB than（4,4）-scheme 8APSK mapping scheme,Gray mapping,Set Partition（SP） mapping,and semi set partition（SSP） mapping of 8PSK respectively. Extrinsic information transfer（EXIT） graph simulation shows that the new scheme can open the decoding channel earlier,further more,it can achieve error-free decoding by iteration.