The Design Of Flexible Sensing Interval And The Data Transmission System Based On USRP In The Cognitive Radio

Cognitive radio(CR) is a kind of new wireless communication technology, which can perceive the environment information, dynamically adjust the radio operation parameters, in order to meet user?s requirements and improve the communication system performance. CR provides a feasible way to solve contradictions between the lack of wirel ess spectrum resources and the growing business requirements, which has gradually become the focus in the academic circles. T he key technology of cognitive radio is learning, action decision and parameter reconfiguration for different environment. T his pap er mainly analyzes and summarizes the CR technology research status. The goal is to establish a CR data transimission experiment system based on the USRP equipments. In addition, aiming at different kinds of user’s Qo S requirements, this paper designs an adaptive adjust ment interval of spectrum sensing in CR in order to adapt the various wireless environments. The method can reduce the system detection delay and the number of detection. T he main work is summarized as follows.Firstly, this paper summarizes a variety of cognitive radio definition and interpretation, and designes a simple, open, scalable and more general framework for cognitive radio. The realization of cognitive radio communica tion system focuses on design and implementation of reconfigurable waveform component. The reconfigurable waveform component use s an open-source SDR technology named GNU Radio to realize a waveform development platform, which consists of a number of adjustable waveform parameters, waveform rapid reconfiguration capability.Secondly, the design of detection interval is a key technology in application scenarios. T his paper designe s an adaptive adjustment interval method of spectrum sensing based on the full consideration about the influence of user signal for data transmission. T he method combines the distribution characteristics of the user signal and the noise signal, which uses the CUSUM algorithm to adjust detection intervals. The method can improve the quality of service, at the same time, which doesn?t affect other users.Finally, this paper design s an anti-jamming communication scenario based on cognitive radio technology in the communication system. Communication system can quickly perceive interference signal(observe), according to the user’s anti-jamming demand(plan), make decisions quickly based on reasoning, adjust the waveform parameters(act) to improve the effectiveness of anti-jamming communications. The experiment shows that the cognitive radio technology is feasible for anti-jamming communications.