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Signal analyzer FM RDS
FM RDS (Radio Data System) is a system that enables the transmission of digital information alongside conventional analogue FM radio broadcasts. It allows radio stations to provide additional data to compatible receivers without significantly affecting the audio signal.
RDS was developed to improve the functionality and usability of FM radio broadcasting by providing information about radio stations, programmes, and alternative transmission frequencies.
Typical bandwidth of FM radio channel with RDS subcarrier is 150 kHz.
FM RDS analyzer decodes the 57 kHz RDS subcarrier from a broadcast FM signal.
- Pilot - quality/SNR of the 19 kHz FM stereo pilot.
- RDS 57 kHz - quality/SNR of the RDS subcarrier.
- Blocks - number of decoded RDS blocks in the current window.
- Groups - number of decoded RDS groups.
- Corrected bits - number of bits corrected by RDS block error correction.
- Station name / PS - Programme Service name, usually the short station name.
- Programme Type
- Country - Home location if present.
- Coverage - Local / International / National / Supra-regional.
- RadioText / RT - longer text message broadcast by the station.
- Clock - decoded Clock-Time group if present.
- Traffic Programme
- Traffic Announcement
- Programme item - programme item number or related programme information if transmitted.
- RT+ - RadioText Plus information if present.
- TMC - Traffic Message Channel information if present.
- EON - Enhanced Other Networks information if present.
- TDC - Transparent Data Channel.
- IH - in-house application data.
- ODA - Open Data Application.
- Alternative frequencies - list of alternate FM frequencies advertised by the station.
RDS decoding needs enough FM signal quality and correct demodulation bandwidth. If the FM signal is weak or distorted, station name may decode first while RadioText and optional data remain incomplete.