The invention relates to a measurement method for a time
delay test of a quadrature
phase shift keying modulator. A relation formula, meeting the requirements of time
delay measurement, of input and output of the quadrature
phase shift keying modulator is given, and a time
delay measurement model is built through the principle of maximum likelihood
estimation. Based on the above, a time delay test
system formed based on a digital
oscilloscope and a
baseband signal and a measurement method for the time delay test are given, and the error components caused by the
manual interpretation of the jump edges of input and output signals are eliminated. When a measurement main
regulator digital
oscilloscope carries out
signal collection at a sampling rate of 25GS / s, the uncertainty of a time delay measurement result is not less than 100ps. The
system is high in measurement accuracy, is simple and feasible in measurement method, is relatively low in requirements for hardware, is high in real-
time response, and can be used for the
link time delay calibration of a high-precision
satellite measurement and control and navigation
positioning system.