Design Of The Digital Processing Circuits Based On DSP For Dynamic Chromatic Dispersion Compensation In 40Gbps Optical Fiber Communication Systems

Nowadays dynamic tunable chromatic dispersion (CD) compensation has become one of the key techniques in the development of high-speed optical fiber communication systems. The compensation system consists of a fast and stable control unit which matches the dispersion compensation devices and the CD monitoring devices together through the algorithm. The above-mentioned algorithm uses the feedback signal detected by the CD monitoring technique to provide the driving signal that is essential for tuning the compensation devices. In this paper, a control unit based on DSP technique in the 40 Gbit/s optical fiber system has been designed, which can realize rapid processing of the CD monitoring signal by the calculation of the algorithm and sending out the driving signal for the CD compensation devices made up of optical switches with segments of dispersion compensation fiber (DCF) links.This thesis mainly focuses on the following aspects:1. The hardware of the DSP control unit and the software cooperating with the hardware were proposed and designed. The whole unit was divided to six modules according to the specific functions. The function of each module and its realization were thoroughly demonstrated. As the algorithm was the key point in the software programming, the design of the algorithm was discussed in the paper and its convergent characteristic was proved theoretically and experimentally.2. Experiments of the DSP control unit were taken, which processed the debug of the I/O interface, the debug of the AD and the debug of the SPI interface to the FLASH. The results proved the validity of the design.3. From a theoretical viewpoint, the compensation principle of DCF and...