光转换单元中锁相环带宽的优化

Optimization of bandwidth for phase-locked loop in OTU

考虑光转换单元(OTU)中锁相环带宽同时受外部输入抖动和内部相位噪声抖动的影响,为克服锁相环带宽选择的矛盾性,本文对其带宽进行了优化设计。在同时考虑外部输入抖动和内部相位噪声的情况下,对锁相环带宽算法进行综合分析。通过改进前人的计算和分析方法推导得出OTU中锁相环带宽的优化算法,分析并得到锁相环路的优化带宽,使OTU的时钟输出有较低的抖动噪声。将优化算法应用到2.5 Gbit/s和10 Gbit/s的OTU中,对环路参数进行定量和定性分析,获得了锁相环的优化参数和再生器输出抖动值。实验研究表明,该优化算法具有一定优越性与可行性,比较适用于OTU。

As both the external input jitter and the internal phase noise jitter impact on the bandwidth of Phase-Locked Loop（PLL） in an Optical Transponder Unit（OTU）,the bandwidth of the PLL was designed optimally to solve the contradiction of the wavelength selection.With consideration of the external input jitter and the internal phase noise,the bandwidth algorithm of the PLL was comprehensively analyzed,and an optimization algorithm of the bandwidth for PLL in the OTU was deduced through improving calculation and analytical methods from formers.The optimal bandwidth of the PLL can ensure the lower jitter noise of clock output in the OUT.The optimization algorithm was applied in the OTUs with 2.5 Gbit/s and 10 Gbit/s,respectively to analyze the loop parameters and the optimal parameters of the PLL and the output jitter value of a regenerator were acquired quantitatively and qualitatively.The experiment shows that the optimization algorithm is superior to traditional algorithms and more suitable for OTUs.