Joint Frequency and Time Domain Frame Synchronization for Short-Reach IM/DD Optical Fiber Transmission Systems

A low-complexity joint frequency and time domain frame synchronization method based on PAM4 training sequence is proposed for short-reach IM/DD systems. Compared with the traditional method, the results in 50 Gbit/s PAM4 transmission systems show the proposed method reduces the computational complexity by 97.09% without performance penalty.