| With the continuous and rapid development of big data,industrial Internet,intelligent equipment and other technologies,the amount of global data has increased sharply,the business flow to be transmitted in the communication network is increasing,and the transmission rate of the communication system is also increasing.However,in the existing transmission system,most of the data exchange functions still need to be completed in the electrical domain,and there is a certain response time for electronic devices,The communication system is affected by the "electronic bottleneck",which leads to certain restrictions on the transmission efficiency of high-speed communication network.Through all-optical signal processing technology,the signal does not need optical-electric and electric-optical conversion in the transmission,amplification,exchange and reception,which greatly reduces the time delay and signal loss caused by photoelectric conversion.In order to improve the transmission performance of highspeed optical communication system,all-optical signal processing technology has become a research hotspot at home and abroad.Based on the study of signal convergence,wavelength conversion and probability shaping theory,this thesis focuses on the joint modulation all-optical convergence method,polarization multiplexing all-optical wavelength conversion method and joint modulation probability shaping signal generation method.The main research contents of this thesis are as follows:(1)In order to reduce the time delay caused by multiple photoelectric conversion in the communication system,a joint modulation all-optical convergence method is proposed.In this method,multiple low-speed optical signals are directly aggregated in the all-optical domain by joint modulation,and converted into one high-speed optical signal without optical electrical and electro-optical conversion.The transmission scheme and performance of joint modulation all-optical convergence method in optical communication system are simulated and studied.The results show that the proposed method realizes the convergence of multi-channel signals in the optical domain,avoids the high time delay caused by multiple photoelectric conversion in the traditional communication system,improves the transmission efficiency and reduces the transmission cost.(2)In order to improve the spectrum efficiency of polarization multiplexed signal,a polarization multiplexed all-optical wavelength conversion method is proposed.This method uses double parallel SOA to realize the all-optical wavelength conversion of polarization multiplexed signal.The transmission scheme of polarization multiplexing16qam signal for all-optical wavelength conversion in optical fiber communication system are simulated and studied.The results show that the polarization multiplexing signal is loaded onto the newly generated wavelength light in the transmission process,and the flexibility and spectrum efficiency of polarization multiplexing signal transmission in high-speed optical communication system are improved.(3)In order to improve the transmission rate and spectrum efficiency of joint modulation all-optical convergence method,a generation method of joint modulation probability shaping signal is proposed and optimized by algorithm.The transmission scheme of.probability shaping 16QAM signal generated by joint modulation of one probability shaping QPSK signal and one QPSK signal are simulated and studied,as well as the transmission performance of polarization multiplexing joint modulation probability shaping signal in all-optical wavelength conversion.The results show that the proposed method not only realizes the generation of probability shaping signal in all-optical domain,but also further improves the signal transmission rate and spectrum utilization through all-optical wavelength conversion. |
