Design And Implementation Of Broadband Spectrum Sensing Based On Dynamic Digital Channelization Technology

Digital channelized receiver is suitable for broadband spectrum sensing in complex electromagnetic environment due to its full probability of receiving,real-time processing and simultaneous processing of multiple signals.However,under uniform channel division mode,cross-channel problems are easy to occur,and multi-channel branches lead to huge resource consumption.In this thesis,a broadband spectrum sensing scheme based on analytics-synthesis filter banks is designed.The time division multiplexing and pulsation array technologies are adopted to realize the digital channelization function in real time and efficiently.At the same time,the dynamic sorting and reconstruction of cross-channel signals are performed.The main work of this thesis is as follows:(1)The channelization principle and signal complete reconfigurable conditions based on the analysis-synthesis filter bank structure are studied,and the efficient implementation of the principle structure is derived.A prototype filter design method of approximate complete reconstruction is presented,and the simulation experiment verifies that the structure and method can effectively and quickly realize the parallel channelization receiving and approximate complete reconstruction of multiple signals;(2)Aiming at the cross-channel problem of broadband sparse signals after digital channelization,a time-frequency graph information extraction algorithm is designed in this thesis.By periodically searching the time-frequency graph optimized by morphology,various signals arriving in real time are classified according to the number of channels occupied and assigned to the corresponding integrated filter banks for reconstruction;(3)A signal parameter estimation algorithm based on FCME and multi-segment spectral clustering is studied,and further parameter estimation and signal type classification are carried out on the perception signal output of dynamic channelized structure.The accuracy of the algorithm is verified by simulation;(4)The key modules in the dynamic digital channelization scheme are realized by FPGA,including:the realization of analytical-synthetic filter banks,the realization of autocorrelation detection module,the realization of morphological processing module,and the realization of time-frequency graph information extraction module.By using the fully parallel processing structure,the dynamic channelized signal perception can be realized in real time and efficiently.Meanwhile,time division multiplexing,data multiplexing and other methods are adopted to reduce the difficulty and resource consumption in hardware structure.The hardware simulation of each module is carried out to verify the correctness of the function;Based on field Programmable gate array(FPGA)platform and Matlab platform,the broadband spectrum sensing scheme is implemented jointly.