偏振复用光通信系统中一种极化交织器  

A polarization interleaver in polarization multiplexing optical communication system

作　　者：胡伟国 张建勇[1] 王含颖 HU Weiguo;ZHANG Jianyong;WANG Hanying(Institute of Ligntwave Technology Bejing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学电子信息工程学院光波技术研究所,北京100044

出　　处：《光电子．激光》2022年第1期98-103,共6页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金项目(61671047)资助项目。

摘　　要：由于高阶调制具有比特相关性,从而导致极化码在光通信系统中无法有效的进行信道极化。本文提出了一种适用于偏振复用光通信系统的极化交织器。该极化交织器使用一个统一的编码器对系统的信息比特进行极化编码,再对编码后的序列进行比特交织,打破了高阶调制的比特相关性,降低了对极化码信道极化的影响,提升了通信系统的性能。同时,对比分析了2D和4D调制编码方案,并在解码符号度量计算时加入缩放因子,提升了系统的误码性能。仿真显示,信道为加性高斯白噪声(additive white Gaussian noise, AWGN)时,极化交织方式与传统比特交织编码调制(bit interleaved coded modulation, BICM)相比,在相同的信噪比下误码性能提升了约1个数量级,在加入缩放因子后,系统的误码性能提升了约0.5 dB。在偏振复用16进制正交幅度调制(polarization multiplexing 16 quadrature amplitude modulation, DP-16QAM)相干光通信系统中,在误码率为10;的情况下,4D极化交织方案相比传统BICM方案,性能提升了约1.3 dB。且在不同偏振模色散(polarization mode dispersion, PMD)下,4D调制方案对系统PMD的容忍度比2D调制方案更优。Due to the bit correlation of high-order modulation, polarization code can not effectively polarize the channel in optical communication system.In this paper, a polarization interleaver for polarization multiplexing optical communication system is proposed.The proposed interleaver uses a unified encoder to encode the information bits of the system, and then interleaves the coded sequence, which breaks the bit correlation of high-order modulation, reduces the impact on the channel polarization of the polarization code, and improves the performance of the communication system.At the same time, the 2 D and 4 D modulation and coding schemes are compared and analyzed, and the scaling factor is added in the decoding symbol metric calculation to improve the bit error rate(BER) performance of the system.Simulation results show that compared with the traditional bit interleaved coded modulation(BICM),the BER performance of the polarization interleaver is improved by about one order of magnitude when the channel is additive white Gaussian noise(AWGN),and the BER performance of the system is improved by about 0.5 dB when the scaling factor is added.In DP-16 QAM coherent optical communication system, the performance of 4 D polarization interleaving scheme is improved by about 1.3 dB compared with the traditional BICM scheme when the BER is 10;.Moreover, the tolerance of 4 D modulation scheme to polarization mode dispersion(PMD) is better than that of 2 D modulation scheme under different PMD.

关 键 词：相干光通信 偏振复用 极化交织 缩放因子 

分 类 号：TN929[电子电信—通信与信息系统]