Research On Electromagnetic Spectrum Monitoring And Cognitive Service Technology

The objects of electromagnetic spectrum monitoring are generally all sources of radiation in the space,including enemy(illegal),me,him and natural sources of radiation.The main tasks of monitoring are to detect and measure the time,space(direction),spectrum,polarization,modulation mode,modulation parameters,power and friend or foe properties of these radiation sources.In addition to mastering the electromagnetic situation and the reasonable frequency of supervision,the monitoring results can also effectively utilize,manage and control the frequency system to avoid various electromagnetic conflicts and mutual interference in time.In the national defense and military struggles,electromagnetic spectrum information is also an important strategic and tactical intelligence.It is an important work content of electronic warfare and information warfare,and a large number of electromagnetic warfare behaviors are derived from it.From the time characteristics,the electromagnetic signal can be divided into two categories: continuous signal and pulse signal.The former exists for a long time(for example,more than 1 second),and its spatial,spectral,and modulation characteristics remain unchanged or change slowly.The latter has a short time,and its time and spectrum modulation characteristics are not only variable but also vary greatly and change quickly.Traditional electromagnetic monitoring pays more attention to continuous signals,using spatial and spectral search combining dwelling,limited monitoring capabilities of pulse signals.The electronic warfare system has the ability to receive and process both continuous and pulsed signals,but it focuses on enemy-specific electromagnetic signals and objects,while rejecting other signals and objects as unwanted or interfering signals.Cognitive electromagnetic spectrum monitoring is suitable for providing real-time electromagnetic environment sensing services in the cognitive process for the whole frequency system,and improving the cognitive ability of the whole frequency system.This thesis will study the monitoring and receiving and signal processing techniques which are suitable for both continuous signals and pulse signals,and propose a monitoring system architecture integrating with modern electromagnetic spectrum warfare or electromagnetic system cognition?technical requirements that meet the needs of modern electromagnetic spectrum monitoring?system components?key technologies and breakthroughs to address simultaneous monitoring of continuous signals and pulse signals.In the construction of cognitive processing module,in addition to constructing cognitive frequency measurement and cognitive measurement,an adaptive spatial domain filtering module is added.The method mainly uses adaptive filtering technology on the basis of digital multi-beam to solve the problems of simultaneous monitoring of continuous wave and pulse signal.This thesis focuses on the cognitive monitoring for signal frequency and spatial parameters of cognitive frequency monitoring systems.And Cognitive digital channelization frequency measurement and cognitive digital multi-beam direction finding are proposed,which is to perform real-time adjustment of channel parameter setting based on digital channelization and to adopt implementation method of cognitive processing based on digital multi-beam formation including real-time adjustment of antenna beam parameter settings to complete frequency measurement estimation and direction measurement.At the same time,this thesis aims to use cognitive monitoring to ensure that the optimal frequency band is selected by wireless communication,and researches the new gray wolf optimization spectrum solving algorithm to make it seamlessly coupled with cognitive monitoring to provide cognitive services for electromagnetic communication.Through simulation experiments,it is proved that the cognitive monitoring proposed in this thesis has significant superiority and accuracy compared with traditional monitoring,and solves the simultaneous detection of pulse signals and continuous wave.And the grey wolf optimization is adopted to provide the best cognitive service for communication.