Work

High-fidelity WDM/SDM fronthaul system based on state-continuous variable-bit coding and sparse residual enhancement

Year: 2026

Type: article

Abstract: We propose a WDM/SDM fronthaul system integrating state-continuous variable-bit source coding and sparse OFDM-domain residual enhancement. The encoder adaptively assigns 3–6 bits according to RF-waveform activity while preserving recursive coding states, reducing the source rate to 5.05 bits/RF sample with 2.72% OFDM EVM. A K20 sparse residual layer lowers the EVM to 1.83% at a total useful source rate of 5.23 bits/RF sample, which remains 12.8% below fixed 6-bit coding. Using 20-GBaud PAS-PAM8, a 33-line electro-optic comb, and a 3-km seven-core MCF link, all 231 wavelength–core combinations are experimentally evaluated. The configured system corresponds to an aggregate net information rate of 11.55 Tbps, with all measured BERs below 2.4 × 10 −2 and most channels achieving 1.8%–2.0% EVM.

Source: Optics Express

DOI: 10.1364/oe.613111