Particle swarm optimization used as a control algorithm for adaptive PMD compensation

We introduce particle swarm optimization (PSO) into adaptive polarization-mode dispersion (PMD) compensation in a 40-Gb/s optical time-division-multiplexing communication system. In the searching process for automatic PMD compensation, the PSO algorithm has the merits of rapid convergence to the global optimum, without being trapped in local suboptima, and good robustness to noise. In this letter, we describe how to implement PSO as a component of a control algorithm in adaptive PMD compensation. Performance comparisons between global and local versions of PSO were carried out theoretically and experimentally. We also demonstrate that a time-varying PMD can be successfully tracked using the PSO technique.