Research And Implementation Of Wideband Spectrum Sensing Tech

With the development of modern wireless communication,CRs is required to to be applied to a wider frequency band,thus wideband spectrum sensing has become an inevitable research hotspot in broadband CRs.Awkwardly,However,the implementation of wideband spectrum sensing technology based on the Nyquist sampling is difficult,such as the need for complex acquisition front-end,high system sampling rates and fast digital signal processors.Compression sensing makes full use of the sparse nature of the spectrum to be perceived,completes the wideband spectrum information acquisition at an analog digital conversion speed well below the Nyquist sampling rate,and performs wideband spectrum sensing in real time with extremely low digital signal processing overhead,can effectively solve the wideband spectrum sensing in the above problems.This paper mainly studies the traditional wideband spectrum sensing technology and compressed spectrum sensing technology,and the algorithm is applied to the wideband frequency hopping communication system to improve the applicability of the system to the electromagnetic environment,and the system interface of the system is developed.The main contents and contributions of this paper include the following aspects:(1)Analyze the research background and development of wideband spectrum sensing technology,the performance of the existing analog information converter(AIC)model is susceptible to the problems of model design defects and model mismatch,and focuses on the compression sampling framework based on the modulated wideband converter(MWC).The frame preprocesses the analog signal in the multi-channel,and through the frame reconstruction,the correlation matrix decomposition and the multi-measurement vector solution,it can estimate the signal support without signal reconstruction and overcome the problem of AIC model mismatch.(2)Aiming at the problem of high cost and high computational cost of support in the wideband compression spectrum sensing method based on MWC framework,and by referring to the framework superiority of MWC,an under-sampled spectrum sensing predecision method for wideband modulation converter is proposed,which is also called channel energy elimination method(CEC).The CEC method utilizes the random characteristics of the received signal,the energy ratio of the different channels is used as the check statistic to detect whether there is a main user signal in the wideband.The theory and simulation show that the CEC algorithm can accurately detect the existence of the primary user signal in the case of low SNR and without any prior knowledge of the main user.And effectively reduces the influence of non-sparse wideband Gaussian white noise on undersampled spectrum sensing,and improves the accuracy of spectrum sensing.By inserting the CEC module between the compressed sample and the support refactoring,it is possible to interrupt the reconstruction of the white noise that is not sparse in the time domain and to improve the correctness of the ensemble reconstruction at a relatively low computational cost,making the CS algorithm based on MWC framework more practical.(3)The wideband spectrum sensing technology and frequency hopping technology are combined to apply to the wideband cognitive frequency hopping communication system to improve the reliability and anti-jamming performance of the frequency hopping communication system in the complex electromagnetic environment.The system framework of wideband frequency hopping communication system based on cognitive is proposed,and this chapter focuses on the spectrum sensing framework,the interaction between the spectrum sensing module and the data communication module,the realization process of the PC client software,the interface analysis of the spectrum sensing,etc.The system can change the transmission parameters according to the electromagnetic environment in the channel,realize the communication in the non-interference frequency band,and utilize the spectrum resources to the greatest extent.Finally,this paper completes the development of the client software of the system on the software platform,the client software can achieve data communication,spectrum sensing,spectrum display and analysis functions.