Software Design And Implementation Of Vector Signal Demodulation And Multi-domain Analysis

With the rapid development of IOT technology and the rapid update and iteration of terminal smart devices,test instruments also need to do a series of update iterations.Therefore,the design and implementation of the signal demodulation algorithm in VSA and the multi-domain analysis of the signal have become the key points of modern vector analysis software.According to the development trend of VSA software,this paper will do in-depth research on the design and implementation of the demodulation algorithm for signals of various modulation formats,and also make corresponding research on the multi-domain analysis of the signal.This article will analyze the software requirements of these two aspects,and write the VSA software based on the multi-domain oscilloscope according to the requirements.The main research contents of the paper are as follows:1.Demodulation methods of various modulation formats of vector signals,including mathematical modeling of n-ASK/n-FSK/n-PSK/n-QAM signals,and in-depth research on each module of demodulation,including matching The algorithm design and software implementation of filter module,digital quadrature down-conversion module,timing synchronization module,carrier synchronization module and equalization module.Among them,the timing synchronization module focuses on the realization of the Gandner symbol synchronization algorithm,and the carrier synchronization module focuses on the realization of the polarity decision and phase discrimination algorithm.2.Multi-domain analysis function of vector signal: It mainly studies the multidomain of VSA software,including time domain,frequency domain,modulation domain and code domain.The main signals studied by VSA software are the original and demodulated I signal,Q signal and IQ signal.The time domain includes time domain plots of these signals,such as amplitude time-time,EVM-time,phase-time,and powertime of I/Q signals,etc.The frequency domain includes various types of spectrograms.The modulation domain includes waterfall plots of these signals.The code domain includes constellation diagram,vector diagram and eye diagram.Symbol error table,including errors such as EVM,magnitude,phase,IQ offset,IQ gain,and IQ quadrature imbalance.And designed a beautiful UI display interface.At the same time,the data processing methods used in this paper are summarized.Through the research and design of the above content,the demodulation and multidomain analysis of the vector signal are finally completed in the multi-domain oscilloscope,and the verification is carried out to prove that it meets the requirements.