Automatic PMD Compensation by Unsupervised Polarization Diversity Combining Coherent Receivers

A new automatic scheme to compensate the intersymbol interference caused by fiber polarization mode dispersion (PMD) is introduced. The proposed method makes use of the orthogonal polarization components by combining them through adaptive electronic filters, which are adjusted through a low-complexity unsupervised updating method. The simplicity of the proposed unsupervised method is its most critical feature in terms of enabling real-time and all-hardware implementation. Simulation results are provided for a fiber channel with 40 Gsymbols/s signalling rate and a mean DGD level greater than the symbol period, where it is demonstrated that the PMD can be effectively compensated with a 2 dB signal-to-noise ratio penalty relative to PMD-free channel.