Re: [Discuss-gnuradio] Miller encoding

[Matt Ettus]

Max Moser wrote:
> Hi there, i research some rf stuff and did it so far with a radio
> scanner and a soundcard, but lately we have aquired now a fine
> hardware with the right boards. So i wanted to start to port this to
> gnu radio.
> It seems to be a miller encoding on top of the FM/FSK signal. I didn't
> find so far an implementation in code in the internet. I hacked
> something together but am unsure about the correctness.
>
> Does someone here have experiences in miller decoding.
>

I found this on wikipedia --

    http://en.wikipedia.org/wiki/Delay_encoding

Sounds like a very strange encoding.  My suggestion would be to do a
quadrature demod on the FSK, and then treat the resulting signal as if
it is at double to specified bitrate.  That way there is no concept of
some things happening in the middle of the symbol and some at the end. 
Use an MM timing recovery loop to get symbols out, use a simple slicer,
and then write some simple code to decode the double bit rate symbols.

Matt