Research On Time Jitter Processing In High Speed Real-time Sampling

Since Moore's Law was found,Digital circuit technology has been developed by leaps and bounds,with frequency and precision increasing rapidly.Correspondingly,signal sampling,especially sampling of high-speed signal has become an urgent requirement in many fields.The time-alternation sampling system proposed by scholars has well realized this function,and many single-chip low-speed Analog-to-digital Converters have been used to effectively replace high-speed ADC,successfully avoiding the problem of insufficient hardware performance and realizing high-speed sampling.However,in the engineering application,the actual finished product TIADC(time-interleaved Analog to digital Converter)system has a variety of errors due to the production process and other problems,so that in the actual sampling,it has a typical periodic non-uniform characteristics,which seriously affects the sampling results.Therefore,it is necessary to estimate and calibrate the signal error so as to reconstruct the signal accurately.Sampling error can be divided into deterministic bias and random jitter.This paper mainly focuses on the research of random jitter,explores its impact on signal-to-noise ratio,and deeply studies its measurement and compensation algorithm.The main research contents of this paper can be divided into two aspects.(1)The random time jitter in multi-channel high-speed sampling system is deeply analyzed,and the time jitter model of sampling system is established.According to the classification of jitter model,the influence of different kinds of jitter noise on the overall signal-to-noise ratio of sampling signal is simulated and analyzed.The quantitative relationship between time jitter and phase noise is discussed,and the method of using phase noise to observe jitter is discussed.(2)The measurement and compensation algorithm of time jitter in sampling system is studied.According to the existing measurement method of sinusoidal signal jitter in high-speed serial system,a universal measurement method of time jitter is designed.The measurement method of various types of known input signals in sampling system is greatly extended the application scope of the algorithm.Based on the measurement algorithm,a compensation algorithm is designed to improve the signal-to-noise ratio of the system under the influence of time jitter.The compensation of high frequency signal is emphatically explored,and the common three-point method is improved to improve the compensation performance of high frequency signal.