Wang Dawei, Jiang Hao, Liang Guowei, Zhan Qianxin, Su Zikang, Li Zhaohui
Opt Express. 2021 Jun 21;29(13):20387-20394. doi: 10.1364/OE.430955.
Chromatic dispersion (CD) equalization is one of the core tasks of the digital signal processing (DSP) chain in modern optical coherent receivers. A conventional impulse-invariant method for designing the CD equalization filter is revisited, improved by proper weighting, and reinterpreted as a Fourier series. To improve upon a direct evaluation of the passband least-squares (LS) approximation, we propose to design a CD equalization finite impulse response (FIR) filter based on a discrete LS approximation. The proposed method avoids numerical evaluation of nontrivial functions and relies only on Fourier transform. Its flexibility is corroborated by a filter design demonstration of joint matched filtering and CD equalization.
色度色散（CD）均衡是现代光相干接收机中数字信号处理（DSP）链的核心任务之一。重新审视了一种用于设计CD均衡滤波器的传统脉冲不变方法，通过适当加权进行改进，并重新解释为傅里叶级数。为了改进对通带最小二乘（LS）近似的直接评估，我们提出基于离散LS近似设计CD均衡有限脉冲响应（FIR）滤波器。所提出的方法避免了对非平凡函数的数值评估，并且仅依赖于傅里叶变换。联合匹配滤波和CD均衡的滤波器设计演示证实了其灵活性。
