Low-overhead joint pre-distortion and QDA equalization scheme in 100-Gb/s PAM4 signals IM/DD-based system

In this paper, a low overhead joint look-up table (LUT) and quadratic discriminant analysis (QDA) scheme is firstly presented to realize the compensation of inter-symbol interference (ISI) in the high-speed short-range intensity modulation and direct detection (IM/DD) system. Here, the LUT is employed to mitigate the signal distortion by generating pre-distorted signals, and the QDA is utilized to equalize the received signals that without requiring the extra complex optimization algorithm. A 100-Gb/s 4-level pulse amplitude modulation (PAM-4) IM/DD simulation transmission system is established to verify the effectiveness of our proposed scheme. The results show that the proposed LUT-QDA reduces the training sequence length by 76% and the number of taps by 63% compared to Volterra, and outperforms the Volterra and QDA by almost 1.3 dBm and 1.5 dBm at 20 km standard single-mode fiber (SSMF) transmission, respectively.