Pulse Position Modulation

GNU Radio
#1

Looking for some help in creating a Pulse Position Modulation block. I
haven’t seen anything on the latest versions of uhd + gnuradio. My only
starting point is to use the time_spec for determining when my pulses
will
be transmitted. Does anybody have experience with this type of
modulation
and how I could possibly implement it within gnuradio??

Any discussion would be helpful at this point.

Thank you
-Dom

#2

On Thu, Dec 15, 2011 at 8:39 AM, Domenic Magazu III [email protected]
wrote:

Looking for some help in creating a Pulse Position Modulation block. I
haven’t seen anything on the latest versions of uhd + gnuradio. My only
starting point is to use the time_spec for determining when my pulses will
be transmitted. Does anybody have experience with this type of modulation
and how I could possibly implement it within gnuradio??

A PPM receiver is pretty easy, my mode S receiver has an example.
Generating PPM should be even easier. You don’t need to use time_spec
at all, just write a block that takes byte data as input and outputs a
string of 1’s and 0’s separated by the number of samples appropriate
for your PPM at the desired sample rate. You can then mix up or down
or filter that stream however you like.

Look at another modulator, like BPSK for instance, to get an idea how
digital modulators are written in Gnuradio.

–n

#3

I think the ADSB project on CGRAN
(https://www.cgran.org/wiki/gr-air-modes)
implements a PPM demodulator. I have not confirmed this but it seems
like a
good place to start.

Evan M.

From: [email protected]id
[mailto:[email protected]id] On Behalf Of
Domenic Magazu III
Sent: Thursday, December 15, 2011 9:40 AM
To: [email protected]
Subject: [Discuss-gnuradio] Pulse Position Modulation

Looking for some help in creating a Pulse Position Modulation block. I
haven’t seen anything on the latest versions of uhd + gnuradio. My only
starting point is to use the time_spec for determining when my pulses
will
be transmitted. Does anybody have experience with this type of
modulation
and how I could possibly implement it within gnuradio??

Any discussion would be helpful at this point.

Thank you
-Dom

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