Improved multiplier-free Mueller-Müller Baud-rate timing error detector for optical IM/DD system
Shenmao Zhang, Linsheng Zhong, Yang Zou, Mingyue Zhu, Xiaoxiao Dai, Jing Zhang, Mengfan Cheng, Qi Yang, Chen Liu, Lei Deng, Deming Liu
Abstract
Baud rate clock recovery scheme that supports high order modulation formats is an essential part in digital signal processing for current short reach transmission. In this paper, we propose an improved multiplier-free Mueller-Müller timing error detector (MMTED) sampling at baud rate, which shows excellent performance with low complexity. Using the sign operation, the multiplier is eliminated. The further use of error signal to substitute the original data helps to reduce the jitter of the clock. 25 GBaud PAM-4/8 and 50 GBaud PAM-4 transmission are carried out to evaluate the TED performance. Compared to the sign MMTED, more than 12 dB timing jitter improvement is realized.