Adaptive Hybrid Iterative Linearization Algorithms for IM/DD Optical Transmission Systems

For optical field recovery and linear dispersion compensation, we propose a performance-enhanced linearization algorithm, termed adaptive hybrid multi-constraint iteration algorithm (MCIA), which does not require any physical modifications to standard configurations of intensity-modulation direct-detection (IM/DD) transmission systems. To improve the sensitivity residual inter-symbol interference (ISI) effect, introduce, after fiber backward-propagation, feed-forward equalizer (FFE) pair into proposed algorithm. estimation errors, utilize two-stage estimator coupled with G-S iteration. After 100-Gb/s PAM-4 signal transmissions over 400-km fibers, simulation results show that MCIA offers 1.5-dB signal-to-noise ratio (OSNR) gain 1-dB power budget improvement compared decision-directed data-aided iterative (DD-DIA), for highly dispersive IM/DD transmissions. By performing estimation, has higher tolerance errors in length. Moreover, cases subject large dispersion, usage embedded FFE only desensitizes on limited bandwidth but also accelerates convergence performance reaching lower BERs. We experimentally demonstrate can support 150-Gb/s 25-km single mode fibers (SSMF), where just 7-tap FFE-pair is required. 150 Gb/s transmissions, length error increased from 0.9 km 20 km.