Hardware Design And Anti-jamming Technology Of Waveform Diversity Array Transmitting Signal

With the development of electronic components,the interference signal generated by the jammer is increasingly approaching the electromagnetic wave reflected back by the real target.Since the emission pattern of traditional phased array radar is only related to the angle,it is difficult to obtain more dimensional information of the target,so that the main lobe deception jamming seriously affects the detection performance and tracking ability of the traditional radar on the target.It brings a huge challenge to the radar anti-jamming algorithm.Waveform diversity array radar is a new type of radar that adds tiny time delay,frequency offset or pulse coding to the transmitted signal,providing more dimensional information of the target.It provides new ideas for the research of target detection,clutter suppression and anti-jamming technology.At the same time,the waveform diversity array radar needs signal modulation at the transmitting end,which makes its system design and interference processing more complicated.Therefore,it is of great significance to study the hardware design and anti-jamming technology of waveform diversity array radar transmitting signals.This paper mainly studies the hardware design and anti-jamming technology of waveform diversity array radar for two waveform diversity array radar systems,frequency diversity array radar and array element pulse code radar.The main work can be summarized as follows:1.The signal models of target and jamming under frequency diversity array(FDA)-multiple input multiple output(MIMO)and element pulse coding(EPC)-multiple input and multiple output(MIMO)waveform diversity array radar system are established.Firstly,the working principle of the jammer to generate deceptive jamming based on the digital radio frequency storage technology is introduced.Secondly,the characteristics of the emission pattern under the frequency diversity array radar system,and the expression of the target and mainlobe spoofed jamming echo signals are analyzed.It is found that adding a small frequency step at the transmitting end makes the FDA-MIMO radar have the coupling characteristics of range and angle,resulting in the difference between the mainlobe interference and the target in the transmitting dimension.Therefore,the target and the interference can be distinguished in the transmit-receive dimension.On this basis,the characteristics of the emission pattern of the array element pulse coding radar,and the expressions of the echo signals of the target and interference under this system are analyzed.It is found that the addition of pulse coding at the transmitter makes the EPC-MIMO radar have the coupling characteristics of the pulse angle,resulting in the difference between the mainlobe interference and the target in the pulse dimension.Therefore,the target and interference can be distinguished in the transmitreceive dimension,and the effectiveness of the waveform diversity array radar against mainlobe spoofing jamming is verified by simulation.2.The problem of hardware design and system implementation scheme of waveform diversity array radar transmitter module is studied.Firstly,the composition of the transmitted signal under the radar system of phased array,MIMO,FDA-MIMO and EPC-MIMO is analyzed,and the modules that need to be built in FPGA are summarized.Secondly,each module is developed and implemented based on FPGA,and the results of functional simulation are compared and analyzed with the data of each node of MATLAB signal processing to verify the effectiveness of the designed waveform diversity array radar transmitting hardware module.Finally,the scheme of the waveform diversity array radar system developed by the team is introduced,and the designed transmitting module is configured in different working modes,and the ability of target detection and interference detection is verified by analyzing the measured data.3.Research on the mainlobe spoofed jamming suppression of EPC-MIMO radar.Firstly,the difference between repeating mainobe spoofing jamming and target signal under the system of array element pulse coding radar is analyzed,and secondly,a method to suppress mainlobe jamming by using the mismatch of pulse code between jamming and target is studied.Finally,configure the waveform diversity array radar transmitter module to work in the EPC-MIMO mode to conduct the external field anti-jamming experiment,and compare it with the measured data processing results in the MIMO mode.The results show that the interference suppression performance of the proposed EPC-MIMO radar anti-mainlobe spoofing jamming algorithm is improved by 10 dB.