Voice mute method in civil aviation VHF anti-interference transceiver

Abstract

The invention discloses a voice silencing method in a civil aviation VHF anti-interference transceiver, and the method comprises the following steps: judging whether a signal exists or not or whetherthe quality is good or not by adopting a carrier frequency estimation method based on a Goertzel algorithm; judging whether a voice signal exists in the signal or not by adopting a voice detection method based on a cyclic average amplitude difference function (CAMDF); and adaptively adjusting an audio mute threshold in combination with an AM modulation degree discriminated by the system in real time to realize automatic on-off of demodulated output voice. According to the method provided by the invention, during normal voice communication, the phenomena of interruption and incapability of turning off some special noises do not occur any more, the voice communication quality problem caused by mute is effectively solved, and the output voice quality grade of the civil aviation VHF anti-interference transceiver is improved.

Description

technical field [0001] The invention belongs to the technical field of voice squelch, and in particular relates to a voice squelch method in a civil aviation VHF anti-jamming transceiver. Background technique [0002] Voice squelch means that in the voice communication mode, when the SINAD (signal-to-noise and distortion ratio) of the voice signal demodulated by the receiver is very poor, the audio output can be automatically turned off to prevent the noise from being unbearable to the listener. In civil aviation voice communication, when the voice squelch is not handled well, it is easy to miss or misjudge, and the voice is intermittent, which greatly affects the normal voice communication between the pilot and the ground control personnel, and affects flight safety. pose great danger. [0003] Common squelch methods mainly include pilot squelch, noise detection squelch, audio detection squelch and carrier detection squelch. Among them, the pilot squelch refers to control...

AI Technical Summary

Problems solved by technology

Among them, the pilot squelch refers to controlling the squelch by detecting whether there is a pilot signal in the demodulated output signal. Its advantage is that the anti-interference ability is relatively strong, and the disadvantage is that the hardware implementation is more complicated, and at the cost of sacrificing part of the transmit power ; Noise detection squelch is to control the squelch by detecting the noise intensity of the high-frequency part of the voice in the frequency discrimination output signal. Poor; audio detection squelch is to achieve voice squelch by counting the noise characteristics on the demodulated output baseband voice signal, but when the noise signal is large, it is difficult to accurately judge whether to turn off the voice output by relying on the voice energy statistics alone; Carrier squelch controls the squelch by detecting the carrier strength of the received RF signal. Generally, the carrier phase-locked loop is used to extract the carrier, and whether to turn off the voice output is determined by judging whether the loop output carrier statistics value is greater than the threshold. The implementation of the method is relatively simple, but it is easy to misjudgment when there is a carrier but no voice. At the same time, because the statistical characteristics of the AM modulation mode have a certain relationship with the change of the modulation degree, it is difficult to determine a suitable carrier threshold in practical applications.

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