Research On Key Technologies Of Compressive Sensing Wideband Receiver

Wideband digital reconnaissance receiver with large instantaneous bandwidthand multi-signal processing capability, assumes an important role in the radarcountermeasures, which has become the inevitable trend in the field of electronicsurveillance. The wideband digital reconnaissance receiver needs high-speed dataacquisition technology to improve the instantaneous bandwidth and needs to useflexible signal processing algorithms to complete the intercepted radar emitterparameters estimation.The high-speed data acquisition technology has been used in existing widebanddigital reconnaissance receiver including the time domain alternating parallelacquisition technique, the parallel acquisition technology based on hybrid filterbank and the frequency domain alternately parallel acquisition techniques. The threetechniques have a common defect, that is, receiver instantaneous bandwidth islimited by AD inherent analog bandwidth.In order to break through the bandwidth bottlenecks of existing widebanddigital reconnaissance receiver, the scheme of a wideband digital reconnaissancereceiver based on compressive sensing has been proposed. The program draws onCS technology for high-speed non-cooperative signal data acquisition, so that theinstantaneous bandwidth of the receivers will no longer subject to the AD inherentbandwidth and meet the wide open monitoring requirement of modern electronicsurveillance equipment. It has the ability of covering the frequency range of radar ina shorter period and completing intercept and parameters measurement of multipleradar radiation sources.In this thesis, the key technologies of CS wideband digital reconnaissancereceiver have been studied, including CS data acquisition, signal reconstruction andsignal parameter measurement algorithm. First, by the study of the distribution ofreconnaissance receive signal and the principles of CS data acquisition technique,the CS parallel data acquisition technique has been explored to be suitable forreconnaissance receiver, which can intercept multiple narrowband signals within awide frequency range. Meanwhile, a CS parallel data acquisition optimization program based on polyphase filter structure has been proposed, which can savehardware resource consumption. Comparing to the traditional parallel acquisitiontechniques, CS parallel data acquisition technology can gain greater instantaneousbandwidth and dynamic range.Secondly, the signal reconstruction algorithm has been researched. The novelfast algorithm for reconstructing acquisition signal of modulated widebandconverter has been proposed, which can solve the pseudo inverse operation problemof typical algorithms and reduce complexity. The simulation results show theimproved algorithm has faster computing speed while maintaining a higherconstruction probability, keep good noise stability, and it can reconstruct a varietyof modulation type signal arriving at the same time.Then, the signal detection and parameters measuring method of the CSwideband digital reconnaissance receiver has been designed. Firstly, according tothe support sets information of reconstructed signal, the signal detection and initialfrequency and bandwidth measurements have been completed, which can direct datarate conversion to reduce the signal data stream, so that the parametersmeasurement can be implemented in DSP. Meanwhile, combined with the parametermeasurement of time domain, the variable step Radon-Ambiguity transformmodulation parameter estimation and frequency domain parameters measurement,the intercepted signal information can be obtained. Because the signalreconstruction is optimization process, reconstructed signal has some distortion.The simulation results show the parameter measurement of a variety of modulationtypes of reconstructed distortion signal can reach certain accuracy.Finally, on the basis of theoretical studies of the CS wideband digitalreconnaissance receiver, the signal processing has been designed, which includeshardware programme design and parameter estimation workflow design while thefunctional simulation of FPGA polyphase filter optimization module has beencompleted. The results of reconstruction and parameters measurement show that themodule and parameter estimation algorithm are effective, which verify that thehardware of signal processing is realizable.