Research On All Optical Aggregation And De-Aggregation Technology In Elastic Optical Networking

In recent years,with the explosive growth of emerging services such as Internet TV,video-on-demand,and cloud computing,users have increasingly demanded the capacity and processing speed of communication networks.However,the traditional WDM optical network is unable to adapt to the needs of network development due to its low frequency utilization and poor flexibility,while the elastic optical network enhances the bandwidth variability on the basis of inheriting the advantages of WDM optical network,and becomes the direction of future optical network development.In the actual communication network,different modulation formats are selected for different networks.Among them,low-speed transmission networks mostly use low-order modulation formats(such as OOK,BPSK,etc.),and high-speed transmission networks mostly use high-order modulation formats(such as QPSK,8PSK,16QAM,etc.).At the switching node of the low-speed transmission network and the high-speed transmission network,realizing the aggregation and de-aggregation of low-order modulation format signals and high-order modulation format signals will effectively save link transmission resources,increase transmission capacity and speed,and rationally channel business traffic.In the elastic optical network,the link aggregation is still in the electrical domain,and the signal needs to be converted optical to electrical at the intermediate node,which is bound to be restricted by the electronic processing speed.The use of all-optical signal processing technology can effectively improve the current processing speed.This dissertation focuses on the aggregation and de-aggregation of all-optical signals,and its main work is as follows:1)OOK signal and BPSK signal are aggregated into QPSK signal.In this paper,based on the cross-phase modulation effect in the nonlinear medium SOA,a scheme is designed to aggregate an OOK signal and a BPSK signal into a QPSK signal.By building the corresponding simulation and experiment platform,the feasibility of the scheme is verified and the performance of the aggregated signal is demonstrated.The simulation results show that at the forward error correction threshold,due to the introduction of noise,the signal-to-noise ratio required to aggregate QPSK signals is increased by 2.6dB compared with the back-to-back QPSK signal.The experimental results show that when the received power exceeds-23dBm,the EVM performance of the aggregated QPSK signal is better than that of back-to-back transmission of QPSK signals.2)The QPSK signal is de-aggregated into OOK signal and BPSK signal.This paper first designed a solution to de-aggregate a QPSK signal into an OOKsignal and a BPSK signal.In the solution,a nonlinear optical loop mirror composed of SOAwas used to obtain and separate the signal and its conjugate harmonics,and then use 90° mixer maintains the gain axis to achieve phase-sensitive amplification and complete de-aggregation.By building the corresponding simulation and experiment platform,the feasibility of the scheme is verified and the performance of the aggregated signal is demonstrated.The simulation results show that at the forward error correction threshold,the required signal-to-noise ratio of the BPSK signal is reduced by 0.7dB relative to the QPSK signal,which achieved a good result.Due to the introduction of noise,the required signal-to-noise ratio of the OOK signal is increased by 2.8dB.The experimental results show that when the received power exceeds-29dBm,the EVM performance of the BPSK signal obtained by the de-aggregation is better than the EVM performance of the back-to-back transmission of the BPSK signal.