Research On Key Technologies Of Embedded Cognitive Radio Monitoring System

Compared to rapidly evolving radio communication technologies,spectrum resources are beginning to become increasingly scarce.In order to solve the problem of low utilization of spectrum resources under the existing static spectrum allocation strategy,cognitive radio theory emerges as the times require.The primary task of cognitive radio implementation is to find and determine the idle spectrum to ensure the next step.Therefore,the thesis designs and develops a visual monitoring system based on embedded-based cognitive radio licensed spectrum,which intuitively displays the spectrum usage of licensed bands,while ensuring the system has real-time and practicality.The embedded cognitive radio monitoring system designed by the thesis is divided into the following parts.Firstly,according to the system requirement analysis,the system technical route is designed,and the whole system architecture is designed,which uses radio frequency circuit as signal acquisition and upper computer as spectrum sensing and visual display.At the same time,the related technology is studied,and the embedded platform with embedded Linux system and Qt software development environment is determined,which lays the foundation for the follow-up development work.Then,the cognitive radio spectrum detection algorithm is deeply studied,and based on the energy detection algorithm,the spectrum sensing module of the host computer is designed to solve the high-speed storage of embedded device data and reduce the drawing time of the visualization module.The storage and perception of the signal data,the output decision results provide data and theoretical support for the visualization module.Finally,the design and programming of the visualization of spectrum sensing results based on Qt graphical interface are completed,and the visualization of signal data in three forms:dynamic spectrum curve,two-dimensional waterfall diagram and three-dimensional spectrum diagram is realized.Then,the system functions are tested and verified by transplanting the related technologies to the embedded platform.The results show that the embedded cognitive radio monitoring system designed in this paper provides users with a good human-machine interface,which is convenient for users to query and access the spectrum usage of the monitoring frequency band,so as to realize dynamic spectrum management in the case of insufficient spectrum resources.Provide a basis for improving spectrum utilization.