Research On Radar Signal Pulse Compression And Interference Cancellation Technology

The emergence of pulse compression technology effectively solves the problem that ordinary radars cannot take into account both distance resolution and operating distance at the same time.However,for the classic matched filtering method,the signal undergoes pulse compression processing will generate large side lobes,which will affect the detection of small targets in a multi-target detection environment.Hence,it is of great significance to study how to suppress the side lobes.At the same time,the integration of radar jamming and radar detection is the general trend of modern warfare.However,during the simultaneous operation of the jammer system and the radar system,the interference signal emitted by the jammer will be coupled to the receiving antenna and mixed into the target signal.Therefore,the problem of removing the interference signal mixed in the echo and obtaining the target information accurately must be solved.The above two issues are the two core aspect studied in this paper.First of all,for the problem of pulse compression processing for large time-bandwidth product signals,this paper compares and analyzes the pulse compression signals,then chirp signals are selected and processed by performs matched filtering pulse compression.Simulation results show that large side lobes are generated by matched filtering pulse compression processing.In order to solve the sidelobe problem,the window function weighting method,adaptive pulse compression algorithm and pulse compression repair algorithm are used to process the pulse compression of the chirp signal.The three methods are compared and analyzed.The results show that the adaptive pulse compression algorithm and the pulse compression repair algorithm can suppress the side lobes effectively.In addition,in order to solve the problem of high computational complexity of the adaptive pulse compression algorithm and the pulse compression repair algorithm with large filter order,a filter bank structure is proposed to first divide the signal into multiple channels.Then pulse compression processing is performed in each sub-channel separately.Finally,the signals are integrated together.This method can effectively reducing the computational complexity of the algorithm.Secondly,in the structure of filter bank multi-channel used by the algorithm,Frequency Response Masking technology is introduced into the polyphase filter bank structure.A low-complexity,narrow-transition-band FRM filter bank structure is designed(applicable to odd arrangement,even arrangement,maximum decimation,and non-maximum decimation).Finally,in the radar interference integrated platform,the interference signal radiated into the space by the transmitting antenna will be coupled to the receiving end,which is mixed into the target echo signal.To solve the problem above,the adaptive echo cancellation algorithm is selected,and the adaptive echo cancellation scheme is designed.The overall block diagram of the system is given.The modules involved are designed and explained.Finally,the system is implemented.The implementation results show that the adaptive echo cancellation scheme used in this paper can effectively achieve echo cancellation.