Abstract: Vector signal generator (VSG) and vector signal analyzer (VSA) have been widely used for the measurement and debugging of digital communication systems. A virtual VSG and a virtual VSA were developed by using the graphical programming language LabVIEW which belongs to American National Instrument. The analogue electrical interface of the instruments is implemented by using National Instrument Data Acquisition Unit (DAQ). The virtual VSG can generate modulated vector signals based on various digital modulation formats， change the signal bandwidth to pre-allocated spectrum， simulate channel noise, and transmit the modulated signal through analog channel. The generated vector signals can be analyzed by the VSA， which integrates the functions of digital demodulator， spectrum analyzer， oscilloscope， constellation diagram analyzer， bit error rate (BER) tester and error vector magnitude (EVM) tester.

Key words: vector signal, LabVIEW, data acquisition