Abstract:Aiming at the problem that traditional general instruments can’t on-line measure the delay of QPSK multi-carrier signal in a new generation of spread-spectrum TT&C system and BEIDOU system. A method of measuring the QPSK multi-carrier signal delay is proposed. Synchronizing signal is realized low-distortion&long-distance transmission by fiber optics. Multi-carrier signal is successfully separated by FIR filter without nonlinear distortion and the delay from filter was calculable and the delay of QPSK signal is successfully measured by using the technology of enveloping with gate. Measurement system architecture is proposed and the QPSK multi-carrier signal delay measurement system is successfully developed which realized high-accuracy on-line measurement for uplink delay of transponding satellite navigation testing system based on the method.