Research And Engineering Realization Of High-speed Data Acquisition Technology Based On Time-interleaved Sampling System

With the development of the wideband digital signal processing technology,the sampling rate of monolithic analog-to-digital converter has been unable to meet some of the high-performance applications.Time Interleaved ADC technology uses multiple ADCs to achieve high-speed acquisition,which realizes the contradiction between sampling rate and resolving.It is the most commonly used high-speed acquisition solution.Due to the reasons of the system architecture,the TI-ADC acquisition process will produce offset-mismatch,gain-mismatch,time-mismatch and frequency-mismatch,which can seriously affect the performance of the system.The background of this thesis is ‘The research of XX'.The dissertation studies the methods of mismatch estimation and mismatch compensation,and realizes high-speed acquisition system based on TI-ADC.The main contents of the dissertation are as follows:In the first part,the model of TI-ADC system is established.This dissertation studies offset-mismatch,gain-mismatch,time-mismatch and frequency-mismatch of TI-ADC system,and analyzes the position of the mismatch harmonic frequency point and the influence on Signal to Noise and Distortion Ratio(SNDR).The second part of this dissertation verifies the mismatch error estimation algorithm based on data statistics and the mismatch error estimation algorithm based on sinusoidal signal fitting.Based on it,a new measurement method of channel mismatch function is proposed.In the third part,this dissertation is mainly about the algorithm of mismatch compensation.Firstly cubic spline interpolation is introduced.The advantages and disadvantages of the algorithm are analyzed.Then an improved algorithm based on perfect reconstruction filters is presented,and simulation results show the effectiveness of the algorithm.In the fourth part,this dissertation discourses the engineering implementation technology of high-speed acquisition and storage system based on TI-ADC.The implementation scheme of the acquisition subsystem and storage subsystem is detailed.Finally,the rationality of the design of the acquisition system and the correctness of the channel mismatch compensation algorithm are verified by processing the actual measured data.