Low Complexity Optical Multipath Interference Mitigation Using Long-Term Memory Postfilter in IM-DD System

We propose a low-complexity clustered long-term memory postfilter to whiten the MPI noise in high-speed IM-DD systems. Experiments with 112 Gbit/s PAM-4 transmission show that the signal-to-interference ratio tolerance can be improved by $\gt4.6 \mathrm{~dB}$.