PSK demodulation of a sub-carrier sent over FM

GNU Radio
#1

Hello,

I had experimented with simple PSK reception with GNU-Radio when the
carrier is directly phase modulated.

However I would like to know how can I demodulate a PSK transmission
which
is carried over a typical FM signal.

Kind regards,

Raydel

#2

Raydel Abreu (CM2ESP) wrote

However I would like to know how can I demodulate a PSK transmission which
is carried over a typical FM signal.

IIRC you would just do the WBFM demod, then the PSK demod. See the
gr-rds:
https://github.com/bastibl/gr-rds

Lou

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#3

On 10/22/2014 11:27 PM, madengr wrote:

Raydel Abreu (CM2ESP) wrote

However I would like to know how can I demodulate a PSK
transmission which is carried over a typical FM signal.

IIRC you would just do the WBFM demod, then the PSK demod. See the
gr-rds: https://github.com/bastibl/gr-rds

That sounds correct. I know hams sometimes do this to get better
transmissions when using their HF gear.

M

#4

Thank you Lou and Martin.

Will try and take a look. One more thing is there any extra to do if the
PSK signal is ±67 degrees instead of nomal 90 degrees or the PSK
demodulator just handles it as usual.

Thanks,

Raydel

2014-10-23 8:32 GMT-04:00 Martin B. [email protected]:

#5

On 10/23/2014 03:36 PM, Raydel Abreu (CM2ESP) wrote:

Thank you Lou and Martin.

Will try and take a look. One more thing is there any extra to do if the
PSK signal is ±67 degrees instead of nomal 90 degrees or the PSK
demodulator just handles it as usual.

I’ve never seen this before, but you’ll have to play around with the
constellation objects. Look at the Python code for PSK for some
pointers.

M