FM signal squelch method, device and system

Abstract

The invention provides a frequency-modulated signal silencing method, device and system and relates to the technical field of wireless communication. The method is applied to a digital software radioplatform and comprises the steps that the sampled signal strength of digital sampled signals corresponding to frequency-modulated signals is obtained; whether the sampled signal strength is smaller than the preset silencing threshold value is judged; if the judgement result is yes, the frequency-modulated signals are subjected to silencing operation so that the frequency-modulated signal can entera silencing state. According to the frequency-modulated signal silencing method, device and system, the silencing effect consistency is improved, the accidental burst noise occurring in the silencingprocess is avoided, the DSP computation amount is reduced, accordingly, the DSP resource is saved, and the system stability is improved.

Description

technical field [0001] The present invention relates to the technical field of wireless communication, in particular to a method, device and system for squelching an FM signal. Background technique [0002] In traditional analog FM (Frequency Modulation, FM) radio stations, when the FM signal (FM signal) is weak or the signal-to-noise ratio is low, the frequency discriminator will output audio noise with a large amplitude, and these large-amplitude noises will make listeners It is very uncomfortable, so it is necessary to introduce a squelch circuit, that is, when the energy outside the audio band (>3000Hz) is too large, it can be considered that the current output is invalid, so the audio output is turned off to prevent unnecessary interference to the receiver . [0003] The traditional squelch scheme is based on the energy of the out-of-band noise (>3000Hz) of the audio signal obtained after the frequency discrimination of the FM signal to determine whether to squel...

AI Technical Summary

Problems solved by technology

The traditional analog FM radio squelch algorithm relies on analog circuits, and requires out-of-band filtering, threshold comparison, and other operations. It is suitable for traditional analog frequency discrimination methods, and its squelch effect depends on the accuracy of related components. The discrete nature of the noise reduction results in poor consistency of the squelch effect, and there will be occasional burst noises during the squelch process

[0004] On the digital software radio platform based on DSP (Digital Signal Processing, digital signal processing) (the platform implements digital frequency discrimination by software, referred to as DSP platform), although the traditional squelch mode can still run, but the frequency discrimination needs to be A series of calculations such as audio out-of-band filtering are performed on the final audio signal, which will increase the amount of calculation of the DSP, which will lead to unstable operation of the system

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