Research On All-optical Reconfigurable Matching Technology For Higher-order Modulation Formats

With the development of emerging technologies such as the Internet of Things,big data and cloud computing,people are demanding higher and higher information timeliness and reliability,and this status has promoted the rapid development of high-capacity,high-bandwidth and low-latency optical networks.Optical networks,as the physical layer of communication systems,have received less attention to their security protection aspects due to the characteristics of closed insulation of the transmission medium,fast signal rates and high reliability.Traditional security measures and security protocols are mainly located at the application,transport and network layers.In recent years,with the frequent occurrence of optical network security incidents,a series of security measures have been proposed.One such technology is the photonic firewall,which is designed to detect the security of information carried by optical fibers.The photonic firewall works similarly to a traditional electrical firewall,first evaluating the security of the optical signal,determining whether it is a dangerous signal,and then choosing to discard or release the signal.The advantage of photonic firewalls over electrical firewalls is that they are implemented using all-optical devices,avoiding photoelectric conversion,which not only reduces power consumption,but also improves the efficiency of signal processing.All-optical pattern matching technology is an important part of the photonic firewall.Using all-optical pattern matching can directly identify signals in the optical domain,identify hidden network intrusions and attacks,and select the appropriate defense means according to the set security policy.The focus of this project is to design and implement reconfigurable matching structures for different modulation formats,and to complete the design of photonic firewalls and the deployment in the network.The research of this project is divided into three parts as follows.1.All-optical matching system for 16QAM.For different modulation formats,the amplitude and phase information contained in the signal during transmission are different,so different matching structures are required for signal matching.The existing studies are applicable to OOK,BPSK,QPSK and 8PSK modulation formats,but not to all-optical matching systems for 16QAM modulation format signals.A feasible solution to match 16QAM modulation format signals is to convert higher order modulation format signals to lower order OOK signals or BPSK signals.Phase compression technique is a common method to convert higher-order modulation format signals into lower-order modulation format signals.After converting the signal from higher-order modulated company to BPSK signal by phase compression,the signal can be matched using the matching structure for BPSK signal.The correctness of the matching structure for the above modulation formats is demonstrated by simulation.2.Reconfigurable matching system for multiple modulation formats.Although the first part implements matching for higher-order modulation formats commonly found in communication systems,different modulation formats require different matching structures for their signals.When a matching system needs to be deployed in a network node,multiple matching systems for different structures need to be deployed,which can greatly increase the complexity of the network node.Reconfigurable matching system is a matching structure that can be applied to multiple modulation formats.This section introduces two reconfigurable structures,one is the reconfigurable matching structure for OOK and BPSK signals,and the other is the matching structure for BPSK,QPSK,8PSK and 16QAM,and the feasibility and noise resistance of the structures are demonstrated in the simulation.3.The design of photonic firewalls and deployment.The structure can be applied to the photonic firewall after reconfigurable matching has been implemented.The matching result can determine whether the signal contains a risky signal or not,and then the result is used to decide whether the signal passes or not,which implements a simple photonic firewall.The deployment of photonic firewalls in the network is also investigated in this section.Photonic firewalls cannot be deployed in all nodes of the network as they are not well developed and require additional power consumption for the nodes.The network nodes for deploying photonic firewalls are obtained using linear programming and heuristic algorithms with the objective of minimizing the spectrum resource consumption and the number of firewalls.