FSK-FM demodulation method and device suitable for large doppler scenario

Abstract

The embodiment of the specification provides a FSK-FM demodulation method and device suitable for a large Doppler scene, wherein the FSK-FM demodulation method suitable for the large Doppler scene comprises: adopting a double automatic frequency control loop cascade architecture; after a baseband signal is obtained by down-conversion of a received intermediate frequency signal, first, a main automatic frequency control loop performs Doppler coarse compensation according to loop parameters configured by a system clock, then, power normalization processing is performed on the compensated signal, then, a secondary automatic frequency control loop performs residual Doppler fine compensation according to loop parameters configured by the system clock and an integral multiple, and finally, a demodulation signal is output through judgment. Two frequency point branches of the secondary loop independently phase detect and are combined to drive a local carrier after loop filtering, so as to realize fine tracking of residual frequency offset. The application can effectively expand the Doppler tolerance range, and improve the demodulation reliability of a telemetry link and the link continuity in a high-speed relative motion scene.

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