Digital signal processing algorithms for high-speed coherent transmission in optical fibers

Digital Signal Processing (DSP) is an indispensable technology for next generation 100 Gb/s optical coherent transmission system. The aim of this thesis is to study DSP algorithms to compensate transmission impairments in a 100 Gb/s PolMux-QPSK coherent optical transmission system. The thesis can be divided in two parts: the first deals with testing different chromatic dispersion compensation techniques (Savory's method, adaptive filters and frequency domain method) while the second part is focused on nonlinear transmission impairment compensation using a multispan backpropagation technique. Constant Modulus Algorithm buttery structure and Viterby and Viterby methods are proposed for polarization de-multiplexing and adaptive and for carries phase recovery. Results of the processing, presented in the last chapter, confirm that coherent detection at 100 Gb/s will become feasible in the future using DSP for transmission impairments compensation.