The invention provides a pulse modulation
signal carrier frequency measuring
system. The
system comprises a front-end circuit, a high-speed acquisition card and a host computer, the front-end circuitis used for performing
frequency mixing on a tested
signal and a local carrier and outputting a pulse modulation
intermediate frequency carrier signal to the high-speed acquisition card, the high-speed acquisition card is used for converting the acquired modulation pulse
intermediate frequency carrier signal to a
digital signal and transmitting the
digital signal to the host computer, and the hostcomputer is used for performing a frequency measuring
algorithm based on zero passage judgment and cycle counting on the acquired
digital signal. According to the
system, the measurement of the carrier frequency of the pulse modulation
signal is realized on the host computer so that the overall architecture of the device for realizing the
algorithm is more
software-based, the design thought of
software radio is satisfied, the hardware design is simplified, the
hardware architecture is more universal, the design of the
software algorithm of the host computer is more flexible, and the influenceof signal
jitter noise on a measuring result in a
signal frequency measuring process is optimized; and the precision of frequency measurement is improved by employing a cycle measuring method, zero passage detection and linear interpolation.