A Novel Polar-Coded Probabilistic Shaping Scheme for Optical DMT Interconnection

A novel bit-oriented probabilistic shaping (PS) scheme based on polar-coded bit weight reconstruction (BWR) is proposed and experimentally demonstrated in an intensity modulation and direct-detection optical discrete multi-tone (DMT) interconnection. The BWR is utilized to enhance the weight of bit '0' by dynamic frozen bits shaping in a systematic-like polar encode processing. Compared with the probability-oriented PS schemes employing distribution matcher (DM) with high computational complexity and PS redundancy, and the symbol-oriented ones based on many-to-one mapping with overlapped symbol demapping difficulty, the proposed bit-oriented PS scheme is with the advantages of relatively lower complexity decoder and shaping redundancy-free profile. The experimental results show that 1.34-dB improvement for receiver power sensitivity and 2.52-dB enhancement for systematic tolerance to optical fiber nonlinear effect can be obtained by the polar-coded PS-16QAM DMT signals compared with the unshaped ones in a 5-km optical DMT interconnection system.