Research Of Digital Singnal Processing For Coherent Optical Commintication In Radio Over Fiber Link

Radio Over Fiber system is very important in microwave photonics, not only because it has the advantages in light weight, small size, wide bandwidth and high immunity to electro-magnetic interferences, but also it is a very promising technology, currently has a large range of research At the same time, the digital coherent optical communication with high spectral efficiency and high receiver sensitivity, multi-functional characteristics typical of post-processing functions technology came into being. In recent years, as the high-speed digital signal processor (DSP) technology, and coherent optical communication technology rapid development, based on coherent detection and digital receiving system of growing concern.In this thesis, firstly we introduced the traditional ROF system and the traditional digital coherent optical communication technology. A theoretical study, and their technical advantages and disadvantages of the corresponding analysis were given in this thesis. After the theoretical analysis, in order to solve the ROF link’s traditional problems that exist to enable them to achieve full-duplex transmission, we introduce the coherent optical receiver to the ROF transmission system to detect the received signal. Consider the ROF link characteristics of the digital coherent receiver compensation algorithm, we were focusing on research and build a simulation platform for the frequency locking and phase recovery, linear demodulation, carrier recovery algorithm with theoretical analysis and simulation shows. Finally after the analysis of the corresponding experimental platform to build, BPSK and QPSK signals were experimentally verified. Simulation results and experimental results show that the corresponding digital receiver processing algorithm to complete and improve the signal transmission function.