Radio Data System (RDS)
Radio Data System (RDS) and its North American variant, Radio Broadcast Data System (RBDS), are data modes transmitted on subcarriers of commercial FM radio station transmissions. Both RDS and RBDS are identical modulation wise but they have some differences in the format of the data sent. RDS is published worldwide as IEC standard 62106.
The RDS system is Dual Side Band modulated onto the 57 kHzKiloHertz (kHz) 10^3 Hz subcarrier of a commercial FMFrequency Modulation transmitter. The RDS mode transmitted is actually one PSKPhase-Shift Keying signal identically duplicated and mirrored across the 57 kHzKiloHertz (kHz) 10^3 Hz carrier for robustness and redundancy. This individual PSKPhase-Shift Keying signal is about 2.2 kHzKiloHertz (kHz) 10^3 Hz wide, and the combined DSBDual Side Band Modulation modulation of RDS is about 4 kHzKiloHertz (kHz) 10^3 Hz.
The RDS system uses Binary PSKPhase-Shift Keying, with a data rate of 1187.5 bpsBits per second (bps). RDS is used to send data such as time, text data on radio programming, programming type, alternative frequencies, and traffic information.
RDS-2 has been announced and is set to replace RDS.
The RDS subcarrier can be seen at 57 kHzKiloHertz (kHz) 10^3 Hz subcarrier on this multiplex demodulated sideband of a commercial FMFrequency Modulation broadcast.
Samples[edit]
Raw USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) sample of the DSBDual Side Band Modulation signal:
Raw RDS |
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The USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) portion of the DSBDual Side Band Modulation RDS signal only:
A good example of a mixdown of a FMFrequency Modulation audio to hear the RDS: Mixdown Sample
Decoding Software[edit]
- Hobby Level Software
Video Examples[edit]
- My journey into FM-RDS
- Different RDS in different RDS Decoders
- FM RDS Reception with GNURadio and RTL SDR
Additional Links[edit]
- Canadian RBDS Broadcast Info
- WAVECOM Database: ALF-RDS
- Differences between RBDS and RDS Explained
- RDS Radio Data System (Italiano)
- Fujitsu RDS Technical Report
- Wikipedia RDS