FM decoding chip, stereo decoding system and method

Abstract

A stereo decoding system comprises an oscillator, a bandpass filter, a PLL unit and a stereo decoder. The oscillator generates a first signal with a center frequency. The bandpass filter receives a stereo multiplexed signal and the first signal to filter out a pilot signal. The PLL unit receives the pilot signal to generate a PLL output signal. The stereo decoder receives the stereo multiplexed signal and the PLL output signal to separate a left channel signal and a right channel signal from the stereo multiplexed signal.

Description

technical field [0001] The invention relates to a stereo decoding system, in particular to a stereo decoding system and method capable of reducing phase drift during signal transmission and its FM decoding chip. Background technique [0002] Due to the characteristics of frequency modulation (hereinafter referred to as FM) signals, such as better suppression ability and longer transmission distance than amplitude modulation (amplitude modulation) signals, an advantage of FM signals is that they can be transmitted in stereo. When a stereo decoding system receives and decodes a stereo signal, a synchronization signal is needed to separate the left channel signal and the right channel signal from the stereo signal. The degree of separation of the left and right channel signals is determined by the delay between the stereo signal and the sync signal, such as phase delay or frequency delay. If the delay between the stereo signal and the sync signal is too large, the left and rig...

AI Technical Summary

Problems solved by technology

If the delay between the stereo signal and the sync signal is too large, the left and right channel signals cannot be clearly separated

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