Sampling digital coherent receiver for demultiplexing and processing of OTDM signals employing high-order modulation

In this thesis, we present a study of optical communication systems that make use of multilevel modulations and exploits coherent detection with digital signal processing (DSP) and optical time division multiplexing (OTDM). The Matlab modeling of an optical communication system if shown and the different elements of a DSP unit are analyzed. In particular we studied the Chromatic Dispersion (CD) compensation with Time Domain Equalizer (TDE), the Polarization Mode Dispersion (PMD) and polarization rotation compensation with adaptive equalizer, the digital phase estimation with Feed Forward (FF) algorithms and the frequency offset compensation. Next, we present the OTD demultiplexing for optical systems that utilize coherent receivers. A set of numerical simulation has been done for the study of the performance of the model implemented. At last we show the results obtained during a laboratory experiment. A back-to-back transmission of a 4-Channels OTDM QPSK system at 160 Gb/s with coherent detection and digital signal processing has been successfully performed and the results are presented and commented