LAB#7DigitalSignalProcessing详解.PDFVIP

LAB #7: Digital Signal Processing Equipment: Pentium PC with NI PCI-MIO-16E-4 data-acquisition board NI BNC 2120 Accessory Box VirtualBench Instrument Library version 2.6 Function Generator (Tektronix CFG250) Reference: PCI-MIO-16E-4 product information from National Instruments website (). Objectives: The objectives of this experiment are: 1. To introduce you to several fundamental concepts in digital signal processing: periodic signals, Fourier Transform, time domain, frequency domain, spectrum, sampling frequency, leakage and aliasing. 2. To introduce you to the Dynamic Signal Analyzer virtual instrument VI (also called a Digital Spectrum Analyzer). We have discussed the idea of periodic and transient signals and Fourier analysis (both Fourier series representation and Fourier transforms). We have also discussed issues related to sampling: number of samples, rate of sampling, and aliasing. The Virtual Bench Dynamic Signal Analyzer provides the tools necessary to explore digital signal processing: it can acquire an analog voltage signal and display the amplitude of the signal as a function of time. The sampling rate and the number of samples can be set. More importantly, it can perform the Fast Fourier Transform (FFT) on the signal, transforming the signal from the time domain to thefrequency domain . Now is the time to use the VB-DSA to play with these ideas. Dynamic Signal Analyzer The front panel of the DSA looks similar to the VB-Virtual Oscilloscope. The Online Help is quite useful if you run into problems. Input Settings, Frequency Settings and Markers can be found under the Edit menu. Display two graphs; on both of these, select channel 0. On the top graph, display the Time Waveform and on the bottom graph display the Amplitude Spectrum. For Display 1 set it to display the ìreal partî. For