Research And Implementation Of Reconfigurable Radar Digital Receiver

The existing radar receiver has fixed parameters and low degree of automation,which can not be applied to different working modes,which seriously restricts the processing ability of the radar system and does not meet the requirements of the multifunctional integrated radar system,in order to realize the reception of different radar signals through software and hardware programming on a general platform.The research of this thesis is mainly carried out from two aspects.On the one hand,on the basis of studying the development and application of reconfigurable technology at home and abroad,Zynq,a all programmable system-on-chip device of Xilinx company,is selected as the design and development platform after understanding the structure and data interaction mechanism of Zynq,a reconfigurable strategy based on the Zynq platform was proposed.On the other hand,according to the structure characteristics of the digital receiver,combined with the theory of digital down conversion,this paper focuses on the implementation of numerical controlled oscillator,mixer and decimation filter bank.First,improve the traditional NCO implementation method,look-up table method,using 1/4waveform compression method,adding phase jitter method and optimized CORDIC algorithm;Then,the implementation methods of three mixers are analyzed.The mixing method based on CORDIC algorithm and 4 times if sampling structure can greatly save resources and reduce the quantization error caused by multiplication compared with multiplier;Then the CIC decimation filter and its compensation filter are simulated and analyzed,and the cascade number of CIC filter and the type of compensation filter are determined.On this basis,the decimation filter bank has the characteristics of variable coefficient and configurable decimation rate.After the above two aspects of analysis and research,according to the design and development process of hardware and software cooperation,the whole receiver system is built,the overall structure of the receiver system is described in detail,and the front-end acquisition module of the receiver,the data interaction implementation mode based on dual port Bram and DMA are given,so that the receiver system has a complete data flow and configuration flow path.The receiver has two working modes,coefficient configuration mode and dynamic reconfigurable mode.Finally,a test platform is established based on the Zynq-7020 development board and data acquisition board.The actual test results show that the radar digital receiving system based on the reconfigurable technology of Zynq platform can complete the functions of signal acquisition,data transmission and digital down conversion,and can change the generation frequency of local oscillator signal and the decimation rate of decimation filter through receiving parameter configuration instructions,The reconfigurable instruction can be triggered by software to switch between different mixing modes and decimation filter banks,which has good universality.