Based On The Labview Typical Communication Signal Modulation, Parameter Identification And Simulation Studies

U.S. NI put forward the concept of virtual instruments in 1986, introduced a graphical programming software Lab VIEW, which led to a revolution of the instrumentation and automation industry.On the basis of analysis and research of virtual instruments and virtual instrument development platform LabVIEW,this paper realizes the typical communication signal modulationthis paper realizes the typical communication signal modulation and non-real-time automatic modulation recognition,and illustrates the application of the Lab VIEW platform in communication teaching application at the same time.This paper briefly introduced the virtual instrument and the Lab VIEW platform,and the common analog and digital communication signals are modulated according to a mathematical model of signal modulation, gives the modulation method on Lab VIEW and the modulation waveform and spectrum in Figure firstly.Then,modulation signal parameter identification process includes signal preprocessing, feature extraction and classification were discussed.Among them, signal preprocessing session mainly discusses the digital down conversion, sampling, frequency estimation and frequency deviation calibration technology.Characteristic parameter extraction session:identified three basic parameters of the modulated signal,according to the common digital modulation signal choosing suitable parameters, and gives the LabVIEW implementation block diagram.Classification and recognition based on decision theory gives decision tree identification scheme.Simulation to identify 6 kinds of common digital signal on LabVIEW.In the case of signal to noise ratio higher than lOdB, the recognition rate close to 100%.Finally, the paper illustrates the virtual instrument in the field of electronic communication teaching experiment application.