Research On The Non-Coherent Detection Of 100Gbps DP-(D)QPSK Ultra-High-Speed Optical Signals

In the current 100 Gbps fiber backbone network,the DP-(D)QPSK modulation format has become the mainstream modulation format due to its high spectrum utilization,high dispersion tolerance,and strong anti-nonlinear effect.Correspondingly,traditional digital coherent reception technology has also matured.However,with the increasing demand for intelligent optical network monitoring and network security,intelligent access to ultra-high-speed optical signals has become a new problem to be solved.In the context of this application,traditional digital coherent reception technology has exposed the following major problems.Firstly,digital coherent receivers are complex and costly.Secondly,digital coherent receivers are generally used for cooperative communication,which have certain requirements for the signal system,but have poor flexibility and versatility in the context of intelligent communication.In view of the limitations of traditional digital coherent detection technology in intelligent optical communication scenarios,this paper proposes the use of non-coherent detection to achieve intelligent reception of DP-(D)QPSK ultra-high-speed optical signals at 100 Gbps rate.Under the ideal optical fiber channel transmission conditions in the laboratory,regardless of the various damage caused by fibre channel transmission,this paper studies the following problems.(1)Traditionally,non-coherent detection technology is used to demodulate differential signals,but this paper innovatively studies the method of co-demodulation of differential and non-differential signals by non-coherent detection technology,which improves the system flexibility in the context of non-cooperative communication.(2)The time delay dynamic adjustment of the delay line interferometer and the highspeed transevier clock data recovery are studied.The periodicity of the frame synchronization code word in the data bit stream is used to judge whether the received data is correct or not,which guarantees the high-speed transevier reference clock can be locked to the correct range and the data is received accurately in the condition that the data rate is unknown.(3)Data channel alignment technique is studied for different degrees of delay in each data channel.By judging whether there are spaced data bits between the frame synchronization codes,it can be judged whether the data channels are aligned,thereby eliminating bit misalignment between different data channels,and ensuring the correctness of the finally recovered data.(4)The corresponding non-coherent detection system is analysed and designed.By using devices like delay line interferometer,balanced receiver and high-performance FPGA,the intelligent access to 100 Gbps DP-(D)QPSK signals is low-costly achieved.(5)The overall test plan of the system is designed and the initial tests of each module of the system are carried out.