System and method for performing subcarrier decoding on high-frequency signals with subcarrier modulation

Abstract

The invention discloses a system and method for performing subcarrier decoding on high-frequency signals with subcarrier modulation. The system comprises a power regulating circuit, a frequency divider circuit, a digital phase-locked loop circuit, a digital decoding circuit and a display terminal, the power regulating circuit is used for performing power amplification or attenuation on the high-frequency signals so as to control signal amplitudes within a power range necessary for the frequency divider circuit; the frequency divider circuit is used for reducing the frequency of the high-frequency signals to 20MHz or so medium frequency signals with subcarrier frequency information; the digital phase-locked loop circuit is used for presetting the output frequency of a local vibration source and performing orthogonal down-conversion, extracting and filtering, phase discrimination and loop filtering on the medium frequency signals subjected to frequency division and preset signals of the local vibration source to form a phase-lock loop with a controllable oscillator; and the digital decoding circuit is used for extracting error AC signals output by a loop phase discriminator in a loop locking state and performing coherence filtering with one or more known subcarrier signals so as to detect the subcarrier frequency time sequence information carried in the high-frequency signals in real time and display the subcarrier frequency time sequence information through the display terminal.

Description

technical field [0001] The invention relates to the technical field of decoding, in particular to a system and method for decoding subcarriers for high-frequency signals with subcarrier modulation. Background technique [0002] Decoding is an important means to detect the correctness of transmitted signal encoding, and has a wide range of application backgrounds. The traditional decoding circuit usually uses a local oscillator source that generates the corresponding transmission frequency band locally, and locks the phase of the input signal through an analog phase-locked loop. After the loop is stable, the error AC signal output by the phase detector is taken out, and after FFT analysis, it passes through the crystal The filter performs filtering and decoding. [0003] In the traditional way, the subcarrier decoding usually uses an analog phase-locked loop to phase-lock the high-frequency signal, and then extracts the AC component after the phase detector, and performs nar...

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Problems solved by technology

[0005] At present, there is no description or report of the similar technology of the present invention, and no similar data at home and abroad have been collected yet.

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