FM broadcasting text

Question

I was listening to a local FM station from my smartphone using a headset.

While I was surfing over the available bands I saw that few FM stations can broadcast the name of the song/music details (song name, movie, release year) while playing.

While a few stations broadcast their FM brand name using the same.

What features or signal manipulators are they using? Since frequency modulation is for wide or narrow band signals, do they use any special keying methods? If they can broadcast along with FM, how is it done for each song?

score 5 · Accepted Answer · answered Apr 25 '20 at 05:42

5

It is implemented using the so called Radio Data System (RDS). Which transmits the channel name, current song and more on a 57 kHz subcarrier.

Source: https://en.m.wikipedia.org/wiki/Radio_Data_System

answered Apr 25 '20 at 05:42

Jakob Halskov

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I know the wikipedia article says that, but I wouldn't call that a "subcarrier": The RDS signal is on a 57 kHz carrier in the FM-demodulated audio signal. You don't see that 57 kHz in the over-the-air spectrum. – Marcus Müller Apr 25 '20 at 07:52
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That makes sense. So it is ‘hidden’ in The upper nonaudible range of the sound signal before it is modulates onto the carrier in the mega hertz range. – Jakob Halskov Apr 25 '20 at 12:54

FM broadcasting text

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