Research On The Nonlinear High Speed System Based On DOE

With the development of technology and market,the requirement of data bandwidth for cloud,pipeline and terminal equipment is becoming larger and larger,which greatly promotes the use of high-speed transceivers in chips.The problem of signal integrity has become a problem that must be solved in the process of new product development.Generally,engineers use commercial EDA tools to optimize the modeling,simulation and analysis when solving the problem of signal integrity,but it will take a lot of time and cannot get guidance information quickly in the early stage of project validation.The emergence of fast time-domain simulation algorithm solves this problem and can quickly get the simulation results of link system.When engineers use the fast time-domain simulation algorithm for the actual high-speed link,they find that some results are quite different from the transient simulation results.The analysis is due to the non-linear factors in the link.Because the traditional fast time-domain simulation algorithm is based on the linear system,we need to further study the non-linear high-speed link.This paper first addresses the problem that commercial EDA software cannot model and flexibly adjust nonlinear factors.Based on Simulink,a platform for studying nonlinear highspeed link simulation is built.Then,the saturation compression nonlinearity and impedance nonlinearity in high-speed links have been studied,including nonlinear measurement and nonlinear sensitivity analysis.By constructing the response matrix of the link,the principal component analysis PCA and the method of goodness of fit are used to process the response matrix to obtain a non-linear measurement index.The simulation verifies the correctness of the index and solves the problem that there are not the solution of measuring and comparing linearity.In the analysis of the sensitivity to nonlinearity,the effect of a single nonlinear factor on the performance of the eye diagram at the receiver is first studied,and then the DOE orthogonal experiment method in statistics is used to study the influence degree of the single nonlinear factor and the interactive nonlinear factor to the link.The degree of influence of the eye diagram is obtained through simulation and data processing,and it is obtained that the eye diagram at the receiver is most sensitive to changes in saturation and nonlinearity at the transmitter.Through the above research,we have a deeper understanding of the characteristics of nonlinear high-speed links.This paper finally studies the worst eye diagram problem of nonlinear links.By calculating the goodness of fit between the waveforms spelled by different fast time-domain simulation algorithms and the transient simulation waveforms,it shows the impact of nonlinearity on the accuracy of traditional algorithms.Based on the Matlab graphical user interface,a tool for solving the worst-eye diagram of a non-linear link using a multi-order matrix has been developed.The worst eye diagram using the tool is compared with one solved by the traditional algorithm,and the higher-order matrix has better accuracy when solving the nonlinear link,and at the same time can obtain the MER order that meets the simulation requirements.It has guiding significance for the design of nonlinear links.