Study On Echo Reconstruction Method Based On Interrupted Transmitting And Receiving In Radar Radio Frequency Simulation

As one of the effective approaches to target measurement,radio frequency simulations has the advantage of high fidelity,good confidentiality,quality controllability and low cost.In the simulation,it can be solved effectively by using interrupted transmitting and receiving for the mutual coupling problem of transmitting and receiving signals caused by the size limitation of anechoic chamber.However,the echo signal processed by transmitting and receiving is equivalent to partial truncation of the real echo,resulting in the loss of part of the target's characteristic information in the echo,which brings difficulties to the subsequent signal processing,thus the equivalent simulation of the whole process of the field experiment cannot be realized through radio frequency simulation.Based on this,the main research contents of this paper are arranged as follows:1)The time-frequency domain characteristic of the interrupted modulation radar signal is analyzed comprehensively.The fuzzy function of the interrupted modulation radar signal is deduced.The matching filter characteristic of the signal is discussed,and the energy loss and compensation method of the radar signals after interrupted modulation are compared.2)To solve the problem of incomplete echo after interrupted transmitting and receiving,an echo reconstruction method for LFM signal under narrowband and wideband condition is proposed.The evaluation indexes of echo reconstruction results are defined.The general mathematical model of non-ideal signal is given,and the effect of non-ideal factors on target measurement and echo reconstruction performance is analyzed.3)Since the above echo reconstruction method cannot be applied to other kinds of radar signal and complex extended target measurement,a general echo reconstruction method based on compression sensing is proposed in the paper.Based on the random observation of radar echo by interrupted transmitting and receiving signals,the radar signals of different forms are decomposed into sparse representations in different sparse transform domains.Several typical radar signal is selected to simulate and analyze,and the performance of echo reconstruction is evaluated.