频偏条件下的低复杂度主从载波盲相位搜索算法

Low-Complexity Blind Phase Search Algorithm for Master-Slave Carrier Under Frequency Offset Conditions

针对存在残余频偏的光频梳波分复用系统,提出一种基于盲相位搜索算法的主从载波恢复方案,该方案适用于存在频偏的光频梳相干波分复用系统。该系统使用盲相位搜索算法获取主通道的相位噪声,获取的相位噪声进一步用于初始化从通道相位噪声;使用测试相位自适应的相位追踪器对从通道的相位噪声进行校正。通过自适应调整测试相位的个数和中心位置,实现了可容忍频偏的低复杂度载波相位恢复。仿真结果表明,当使用80 GHz间隔的五线光频梳作为发射端和本地振荡光源时,相对于各通道独立的载波恢复方案,本方案在不牺牲相位噪声容忍度的前提下,将从通道的计算复杂度降低了80%。

A scheme for master-slave carrier recovery upon the blind phase search algorithm is proposed in this paper,and the scheme is suitable for coherent wavelength division multiplexing systems based on optical frequency comb with frequency offset.Firstly,the blind phase search algorithm is used to obtain the phase noise of the master channel,which is in turn used to initialize the phase noise of the slave channel.Then,the initialized results are corrected with phase trackers that can test phases automatically.By adaptively adjusting the number and central position of the test phases,this scheme achieves low-complexity tolerant carrier phase recovery of frequency offset.The simulation results show that when a five-line optical frequency comb with an 80 GHz interval is used as the transmitter and the local oscillating light source,the calculation complexity of the slave channel can be reduced by 80%without sacrificing phase noise tolerance compared with carrier recovery schemes that have channels independent from each other.