光学学报, 2018, 38 (4): 0406001, 网络出版: 2018-07-10
基于投影直方图的CO-OFDM系统盲相位噪声补偿算法 下载: 940次
Blind Phase Noise Compensation Algorithm for CO-OFDM System Based on Projection Histogram
光通信 相干光正交频分复用 投影直方图 公共相位噪声估计 optical communications coherent optical orthogonal frequency division mul projection histogram common phase noise estimation
摘要
提出了一种改进的盲相位噪声补偿算法--两阶投影直方图(two-stage PH)算法。利用一系列均匀分布的测试相位对接收信号进行相位旋转,将得到的信号向实轴投影,获取投影直方图;统计投影中心附近星座点的数量,以数量最多对应的测试相位作为粗相移值;以粗相移值为中心均匀取一定数量的测试相位,重复一阶投影直方图的估计步骤,得到精确的相移值进行相位补偿。通过基于光梳状谱的双向相干光正交频分复用无源光网络(CO-OFDM-PON)实验系统对该算法的性能进行了验证。结果表明:该方法对10×8 Gbit/s的 CO-OFDM系统的公共相位噪声有很好的补偿效果,将16正交振幅调制(16QAM) CO-OFDM系统的误码率降低至少2个数量级。该算法测试相位的个数仅需一阶投影直方图算法测试相位个数的1/4,极大地降低了系统的复杂度,可用于CO-OFDM系统的公共相位噪声补偿。
Abstract
An improved blind phase noise compensation algorithm, two-stage projection histogram (PH) algorithm, is proposed. Firstly, we use a series of uniformly distributed test phases to rotate the phase of the received signal, and project the received signal onto the real axis to obtain the projected histogram; secondly, we count the number of constellation points near the projection center and take the test phase with the largest number as the coarse phase shift value; thirdly, we consider coarse phase shift value as the center, take a certain number of test phases uniformly, repeat the estimation steps of the one-stage PH, and obtain the accurate phase shift value for phase compensation. The performance of the proposed algorithm is experimentally verified in the coherent optical orthogonal frequency division multiplexing passive optical network (CO-OFDM-PON) system based on optical comb. The results show that the proposed algorithm has a good compensation effect on the common phase noise of 10×8 Gbit/s CO-OFDM system, and the bit error rate (BER) is reduced by at least two orders of magnitude. Compared with the one-stage PH algorithm, the proposed algorithm need only 1/4 number of test phases, which greatly reduces the complexity of the system and can be used to common phase noise compensation for CO-OFDM systems.
马俊洁, 孙腾雰, 李正璇, 徐悦婷, 汪敏, 张倩武. 基于投影直方图的CO-OFDM系统盲相位噪声补偿算法[J]. 光学学报, 2018, 38(4): 0406001. Junjie Ma, Tengfen Sun, Zhengxuan Li, Yueting Xu, Min Wang, Qianwu Zhang. Blind Phase Noise Compensation Algorithm for CO-OFDM System Based on Projection Histogram[J]. Acta Optica Sinica, 2018, 38(4): 0406001.