Coherent Optical Burst-mode Receiver And Its Application In WDM Optical Networks

Nowadays, because of the rapid development and growth of a variety of new data services on Internet, the demand for network bandwidth and transmission quality are also growing rapidly. There are a large number of theoretical studies about 100 G coherent optical transmission system at home and abroad, which are also mature. What’s more, the optical burst switching network greatly not only improves resource allocation rate and resource utilization compared with the optical path switching network, but also overcome the defects in optical switching and optical buffer technology of the optical packet switching, so it is the most suitable optical switching network. 112 Gbps PDM-QPSK coherent optical burst transmission network is the most promising optical transmission network currently. However, in the concrete implementation of optical burst receiver, hardware processing rate of high-speed real-time DSP with coherent optical signal processing is still faced with the ‘bottleneck’ problem. And when the optical burst receiver applies to WDM networks, channel crosstalk and power jitter generated by the optical burst packet transmission in a multichannel system will also affect the performance of the system. The thesis analyzed and resolved the above two issues of 112 Gbps PDM-QPSK coherent optical burst receiver:Firstly this thesis presented the parallel processing schemes of 112 Gbps PDM-QPSK optical burst receiver taking into account calculating delays due to the feedback in parallel pipeline structure, which were divided into three parts: the parallel processing schemes of equalizer, frequency offset estimation module and co-channel equalization and frequency offset estimation. Then simulation studies have been made, and comparative analysis of the impact of the transmission distance and frequency offset on convergence speed and system performance of optical burst receiver offset was made.Secondly, the structure of equalizer group combined with frequency estimation algorithm was designed for optical burst receiver applications to WDM networks, which will be affected by channel crosstalk, dispersion, noise and frequency offset and other factors. The input of equalizer group were signals from three adjacent channels, channel crosstalk and dispersion of present channel signal could be removed by LMS algorithm, and the calculation of error signals of the equalizer group by using the results of frequency offset estimation could compensate for the equalizer output signal for improving the accuracy of judgment. Finally, the simulation of power jitter of the optical burst packet was made and the impact of power jitter on convergence and system performance of optical burst receiver was analyzed.