Design And Implementation Of High Speed Synchronous Sampling System

High speed acquisition system is widely used in radar positioning,weather,earthquake early warning,aerospace,communication and other fields.In many scenarios,high speed synchronous sampling system is required to accurately and quickly collect,analyze and judge the field high frequency analog signals.In view of the problems of sampling of high frequency signal and real time processing of high speed data in high-speed acquisition system,this paper designs a high speed synchronous sampling system with FPGA as the main controller,which has certain significance in the research and engineering.This paper designs a high speed synchronous sampling system based on ADC+FPGA+high-speed interface.Firstly,a digital downconversion module is designed to convert the high frequency narrowband signal collected by ADC into multiple channels of low frequency baseband signal simultaneously,and the center frequency and data extraction rate of each channel subband can be adjusted,which ensure the real-time performance and improves the flexibility and expansibility of the system.Meanwhile,compared with the existing down-conversion scheme,the filter resources are reduced.Second,a data processing module is designed for the data after down conversion,mainly includes the integral time adjustable FFT spectrum analysis,zero delay autocorrelation and zero delay cross-correlation.The FFT module designed in this paper takes into account flexibility,precision and implementation complexity.Compared with the existing adjustable big points FFT,the FFT module designed in this paper is more simple to achieve under the condition of meeting the accuracy requirements.The high speed synchronous sampling system designed in this paper has been tested and simulated,and the results show that each module of the system has reached the design index,which verifies the rationality and correctness of the system design scheme.