Clock Recovery and Equalization Algorithms for Coherent Optical Communication Systems with Non-Integer Oversampling

With the increase of symbol rate, the sampling rate of the signals is lower than the requirement of Nyquist sampling rate. However, non-integer oversampling causes spectrum overlap and seriously affect the transmission performance. In order to solve this problem, this paper proposes a modified clock recovery and equalization algorithm corresponding to the non-integer oversampling. The experimental results of 20-GBaud SP-16-QAM transmission demonstrate the performance of the clock recovery and equalization algorithms, which can compensate the inherent distortions without additional performance penalty.