Ni Weihao, Li Fan, Yin Mingzhu, Chen Zhiwei, Wang Wei, Zou Dongdong, Cai Yi, Sui Qi, Li Zhaohui
Opt Lett. 2022 Sep 1;47(17):4387-4390. doi: 10.1364/OL.469838.
Maximum likelihood sequence estimation (MLSE) is an optimal solution to realize sequence detection in the digital signal processing (DSP) of short reach O-band intensity modulation/direct detection (IM/DD) systems with bandwidth limitation. However, traditional MLSE requires relatively high computational complexity for short reach optical interconnect. Although the computational complexity of single-symbol sequence detection is quite low, the capability of combating with the inter symbol interference (ISI) is inadequate. To combine the low computational complexity of single-symbol sequence detection with the high reliability of multi-symbol sequence detection in MLSE, decision region partition aided MLSE (DRP-MLSE) is proposed and verified with 60-Gbaud and 65-Gbaud PAM-4 IM/DD systems over 40-km single-mode fiber (SMF) transmission. The experimental results show that the DRP-MLSE can realize similar performance of conventional MLSE with negligible penalty and significantly lower computational complexity.
最大似然序列估计（MLSE）是在具有带宽限制的短距离O波段强度调制/直接检测（IM/DD）系统的数字信号处理（DSP）中实现序列检测的最优解决方案。然而，传统的MLSE对于短距离光互连需要相对较高的计算复杂度。虽然单符号序列检测的计算复杂度相当低，但对抗符号间干扰（ISI）的能力不足。为了将单符号序列检测的低计算复杂度与MLSE中多符号序列检测的高可靠性相结合，提出了决策区域划分辅助MLSE（DRP-MLSE），并在40公里单模光纤（SMF）传输的60 Gbaud和65 Gbaud PAM-4 IM/DD系统中进行了验证。实验结果表明，DRP-MLSE可以实现与传统MLSE相似的性能，代价可忽略不计，且计算复杂度显著降低。
