Research On Blind Processing And Jamming Technology Of WCDMA Communication Signal

WCDMA communication system has been widely used in the fields of mobile communication and military satellite communication because of its high capacity,fast transmission rate and strong anti-jamming ability.Aiming at the problem of huge difficulties for third-party detection,analysis and jamming due to the particularity of WCDMA signals,the thesis first analyzes the structural characteristics of WCDMA signals,and then studies the WCDMA downlink signal cell search scheme in the context of non-cooperation,and finally designs WCDMA jamming waveform and completed the field test of some jamming schemes.Specifically,the following three aspects of research work are mainly carried out.(1)Analyzed the generation process of WCDMA downlink signal,realized the protocol-based WCDMA downlink signal cell search,analyzed the structure and function of the SCH,P-CPICH and P-CCPCH physical channels,utilize the symbol data characteristic of P-CPICH to correct the frequency deviation of the signal.(2)Designed a cell search scheme based on blind processing and machine learning technology in a non-cooperative context.The carrier frequency estimation of the WCDMA downlink signal is completed by calculating the quartic spectrum of the signal.In the case that the primary synchronization code(PSC)is unknown,a blind slot synchronization algorithm based on feature decomposition is proposed,this algorithm is used to effectively estimate the slot start point of the actual detection signal,and on this basis,the PSC production formula is estimated by analyzing the PSC generation process.When the secondary synchronization code and its distribution are unknown,and the primary scrambling code set is known,the classification method based on machine learning and the sliding correlation method based on the autocorrelation characteristics of the GOLD code are used to realize the frame synchronization of the signal and the identification of the primary scrambling code.The method of estimating the PN code of the neural network is improved,and the primary scrambling code of the actual WCDMA downlink signal was estimated using the improved method,and the estimated accuracy rate reached 85%.(3)Designed and studied the jamming waveforms of WCDMA downlink and uplink respectively,and completed the jamming test of some schemes at a certain base.In the WCDMA downlink jamming part,three jamming schemes,PSC jamming,repeater jamming and waveform reconstruction jamming are studied,and PSC jamming is selected for field test verification,the results show that PSC jamming is better than white noise jamming 20 dB.In the WCDMA uplink jamming part,conducted field tests on resourceoccupied jamming,white noise jamming and QPSK jamming,the results show that white noise jamming and QPSK jamming have similar effects,resource-occupied jamming is8 dB better than white noise jamming.