A Digital FM Stereo Decoding Method

A stereo and decoding circuit technology, applied in the field of communication, can solve the problems of weakening the stereo sense of sound and affecting the user experience, and achieve the effects of improving the stereo decoding performance, improving the stereo isolation, and reducing the intermodulation distortion.

Inactive Publication Date: 2012-02-22
SOUTHEAST UNIV
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AI Technical Summary

Problems solved by technology

If the crosstalk between the two channels is large, the three-dimensional effect of the sound will be weakened, which will undoubtedly affect the user experience

Method used

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  • A Digital FM Stereo Decoding Method
  • A Digital FM Stereo Decoding Method
  • A Digital FM Stereo Decoding Method

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Embodiment Construction

[0034] First set forth the principle of the inventive method:

[0035] The demodulated FM signal contains three different components, and its spectrogram is as follows figure 1 shown. Specifically, the demodulated FM signal includes: the sum signal M=L+R representing the stereo left and right channels, which occupies the frequency range from 0 to 15KHz; as required by FCC (Federal Communications Commission) regulations In that way, at 19KHz frequency, there is a 19KHz pilot signal; centered at 38KHz frequency, which is twice the frequency of the pilot signal, the information S=L-R of the left channel minus the right channel is modulated on the DSB- of the suppressed carrier In the SC (double sideband modulation) signal, its frequency band occupies a 30KHz range from 23KHz to 53KHz.

[0036] A traditional stereo decoder restores the sum and difference signals of the left and right channels through the pilot signal, and finally mixes these two signals to obtain the left and ri...

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Abstract

The invention provides a digital tuning stereo decoding method. The method has the following steps: setting a phase difference compensation circuit with symmetrical interior; replacing the prior stereo decoding difference signal generating circuit with the phase difference compensation circuit; decoding a stereo composite signal by a pair of quadrature subcarrier signals; processing the stereo composite signal by the phase difference compensation circuit, and sending the signal to a stereo mixer. The invention eliminates the phase effect of subcarriers, improves the stereo decoding performance, and optimizes the decoding performance.

Description

technical field [0001] The invention relates to the communication field, in particular to a digital FM stereo decoding method in an FM (frequency modulation) receiver. Background technique [0002] At present, FM stereo receivers are widely used in products such as mobile phones, MP3 and FM broadcasting. Traditional FM radio broadcasts are transmitted in a standard stereo scheme. The standard stereo signal spectrogram is as follows figure 1 As shown, the stereo signal is composed of the sum signal M=L+R of the left and right channels, the difference signal S=L-R of the left and right channels, and a 19KHz pilot signal. In addition, the stereo signal may also contain RDS (Radio Data System) signals or RBDS (Radio Broadcast Data System) signals modulated at 57KHz. [0003] The traditional stereo decoding method first needs to recover the 19KHz pilot signal, and obtain the 38KHz stereo subcarrier through this pilot signal. This subcarrier signal is then used to downconvert ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G10L19/00G10L19/26
Inventor 张萌汤佳健高星李红丁小军曲子华朱贾峰吉新村黄福青徐勐
Owner SOUTHEAST UNIV
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