The Performance Research On High-speed And High-efficiency Optical Hybrid Modulation Signal

With the explosive growth of global IP traffic and the emergence of various emerging services,such as the Internet of Things,VR/AR,and 5G,the core network faces great network congestion.The efficient modulation can:(1)utilize the finite bandwidth sufficiently to alleviate network congestion effectively;(2)reduce various damages effectively,improve the bit error rate(BER)performance of the system,and improve receiver sensitivity;(3)reduce the cost of trunk reconstruction by using the existing network.While,the hybrid modulation is more efficient than the single modulation,and the research on the hybrid modulation signal has important research value.Two kinds of hybrid modulation signals are mainly studied in this thesis: one is based on modulation-modulation(M-M)and the other is based on forward error correction(FEC),i.e.FEC-M.This project was supported by NSFC “Reserch on physical layer security and optical coding for free space communication(61671306)”,and JCYJ “Reserch on key technologies of optical communication based on optical encoding physical layer security(20160328145357990)”.The main work of this thesis is as follows:1)The performance of M-M signals combining polarization division multiplexingdifferential quadrature phase shift keying(PDM-DQPSK,PDQ)with m-ary Position Modulation(mPoM)is studied.The spectral efficiency and power efficiency of PDQ-mPoM hybrid modulation signal are analyzed;Based on the theory of information encoding and decoding and traditional PDQ-mPoM encoding and decoding analysis,the BER formula of PDQ-mPoM is deduced,the BER performance under different modulation order and nonlinear phase noise are discussed.2)The performance of M-M hybrid modulation signals in optical label switching(OLS)system is studied,the BER formula for calculating the BER of a hybird modulation signal consisting of a load and mPoM label at different bit rate ratios is derived,taking PDQ-mPoM and DPSK-mPoM system as an example,the BER performance of them is studied.3)The BER performance of FEC-M hybrid modulation signals is studied.Under the condition of different coding schemes,different modulation orders and nonlinear phase noise,the BER performance of FEC,such as Reed-Solomon(RS)and LDPC(Low Density Parity Check Code),hybrid with phase modulation or postion modulation,such as BPSK?DQPSK(Differential Quadrature Phase Shift Keying)?PDQ or PPM(Pulse Position Modulation),are studied,then,comparing them to M-M hybrid modulation.The results of this study provide a reference for improving the spectral efficiency,power efficiency,and the BER performance or receiver sensitivity of the system.It lays the foundation for designing the next generation of efficient and large capacity optical communication system.