Re: [Discuss-gnuradio] RDS decoding

[jean-michel . friedt]

I have just completed the translation to English of my description of
RDS decoding. It is now available at 

http://jmfriedt.free.fr/lm_rds_eng.pdf

Corrections welcome, both on the content (not familiar enough with error
correcting codes and bitrate synchronization to be sure I did't make
mistakes in describing my experiments) and the spelling.

JM

> As briefly mentioned at FOSDEM, I have been investigating RDS since
> last christmas, trying to tackle each issue step by step from LO
> synchronization for BPSK demodulation, bit decoding, sentence
> synchronization, station name and free text extraction, error
> correcting code implementation and finally transferred time analysis.
> My objective was of course not to compete with gr_rds, used as a
> reference, but to acquire a detailed understanding of each step.
> Since I protoype with GNU/Octave, I wanted to convert most digital
> signal processing from LFSR to linear algebra (matrix). I think I
> pretty much understand now the whole process, despite designing the
> error correcting code being still beyond my capability. An internal
> lab presentation on the topic is now available at
> http://jmfriedt.free.fr/slides_rds.pdf and for the French speaking
> audience, accompanying article (in French at the moment, will be
> translated ASAP to English, as soon as I have completed RDS v.s GPS
> time comparisons) at http://jmfriedt.free.fr/lm_rds.pdf
> 
> I am well aware of Tom Rondeau's sponsoring Polyphase clock recovery,
> but at the moment I could only figure out how to use MM-Clock
> recovery and MPSK, which worked quite well for my purpose.
> 
> Any feedback welcome,
> JM
> 



-- 
JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
25000 Besancon, France