Methods And Applications Of Signal Transmitting And Receiving In Radar Hardware-in-the-Loop Simulation

As a typical hardware-in-the-loop(HWIL)simulation,Radar radio frequency simulation(RFS)system is composed of actual equipment,simulator and mathematical model.In radar RFS,the radar,target and simulation parameters can be adjusted easily for target measurement.Compared with field experiment,radar RFS in anechoic chamber has the advantange of low complexity,low cost,high fidelity,quality controllability and good confidentiality.Generally,impulse and swept frequency signals are used in radar RFS for static target measurement.However,the target becomes high speed,high maneuvering and attitude varying,which brings great challenges for the target dynamic characteristic measurement in anechoic chamber.Pulse radar signal,a typical signal for space target detection,is also widely used in target dynamic measurement.Therefore,it is an increasingly demand of RFS to conduct target dynamic meansurement in anechoic chamber with pulse radar signal.Unfortunately,because the space of anechoic chamber is limited and the time duration of pulse radar signal is relatively long,the reflected signal returns before the pulse radar signal is fully transmitted.Then,the transmitted and reflected pulse signals are coupled at the receiver.To solve this problem,the interrupted transmitting and reciving is proposed as the main line of this dissertation.On the background of radar RFS,the transmitting and receiving method of pulse radar signal,target echo reconstruction method and simulaiton application are discussed in this dissertation,which provides theoretical basis for radar HWIL simulation design,target measurement method and application.The main research contents are presented as follows:1.Pulse radar signal uniformly interrupted transmitting and receiving(U-ITR)method in radar RFS.In order to solve the coupling between the transmitting and receiving pulse signals in anechoic chamber,the U-ITR is proposed to transmit and receive the pulse in piecewise.The U-ITR parameters constraints are presented according to the size of anechoic chamber,the target size and the parameters of pulse signal such as linear frequency modulation(LFM)and phase code modulation(PCM).Then,the target echo and range profile reconstruction method are discussed to obtain the target radar cross section.The consistency of target range profile obtained by U-ITR and complete pulse is also analyzed by theoretical derivation and simulation.In accrod with the transient response,the non-ideal U-ITR is modeled to conduct the target measurement finally.2.Pulse radar signal randomly interrupted transmitting and receiving(R-ITR)method in radar RFS.By using the U-ITR method,some fake peaks exist in the high resolution range profile(HRRP)after pulse compression.Specially,the real and fake peaks in HRRP may be overlapped when the target size is large with a fixed period of U-ITR.To eliminate the fake peaks and obtain the precise HRRP in radar RFS,the R-ITR is proposed to transmit the pulse radar signal.Since the transmitting and receiving periods are random,the fake peaks in the HRRP can be reduced.Then,the characteristic of R-ITR control signal,target echo and HRRP are discussed respectively.Furthermore,the compressive sensing(CS)is utilized to reconstruct the HRRP as the echo obtained by R-ITR is piecewise sparse.Simulations with different R-ITR parameters are also conducted to verify the effectiveness of the proposed method.Besides,the optimization method based on genetic algorithm(GA)is proposed to obtain better HRRP reconstruction performance.3.Pulse radar target measurement and application research based on ITR method.The ITR experiment system is constructed for target measurement in anechoic chamber.Target HRRP is obtained with U-ITR and R-ITR method,which verifies the effectiveness of ITR and HRRP reconstruction method.Based on the reconstruction of target HRRP,inverse synthetic aperture radar(ISAR)is simulated in radar RFS.As pulse radar signal can be utilized in ITR method,target dynamic measurement can be conducted with high pulse repetition period(PRF)of pulse signal.Therefore,the target dynmaic measurement expereiment system with ITR is constructed in this dissertation.Then,the the experiments are conducted in anechoic chamber to obtain the micro-Doppler of rotation target and precession target.Finally,the equivalent simualtion procedure of pulse radar countermeasure is provided with the ITR method in RFS.Convolution noise jamming,a typically smart noise jamming,is considered to construct the complex electromagnetic environment(EME)in anechoic chamber.Numerical simulation shows that the target detection results obtained by ITR are consistency with those obtained by complete pulse.The work of this dissertation solves the coupling between the transmitting and receiving pulse signals caused by the limit size of anechoic chamber.Different ITR methods and range profile reconstruction algorithms are provided.The target characteristics such as RCS,range profile and micro-Doppler are obtained with pulse radar signal in RFS,which verifies the effectiveness and practicability of ITR.The study provides theorical method and technology support for the engineering application of pulse radar RFS.