Adding a custom modulation

GNU Radio
1

Hi.

I am testing my custom modulation scheme ppm.py. I followed this post
http://lists.gnu.org/archive/html/discuss-gnuradio/2010-12/msg00265.html
to register this modulation into mods/demods. I added a line

import ppm

in my benchmark_tx.py.

I also tried placing the ppm.py file in blks2impl directory. However
neither method worked. The result from “print
digital.modulation_utils.type_1_mods()” did not contain ppm.

Another issue is that I modified digital_constellation.cc, and I called
functions in the modified digital_constellation.cc in my ppm.py. In this
case should I rebuild gnuradio? If not, what should I do?

Any suggestions?
Thanks!

Fei

2

On Sun, Apr 7, 2013 at 8:00 PM, Ƕ [email protected] wrote:

functions in the modified digital_constellation.cc in my ppm.py. In this

Hi Fei,

The issue is that in the directory benchmark scripts are in isn’t aware
of
your ppm file. You have a few options that you can explore by searching
around for python import path or search path. and doing some reading.
You
can take a look in gr-digital/python/init.py to see how the other
mod/demods are imported. Adding a line in that file “from ppm import *”
should make your ppm stuff show up in Python after rebuilding gnuradio.

And yes, you should rebuild gnuradio. Any time you change C++ source
code
you must rebuild it.

-Nathan

3

Date: Sun, 7 Apr 2013 22:00:40 -0500
Subject: Re: [Discuss-gnuradio] Adding a custom modulation
From: [email protected]
To: [email protected]
CC: [email protected]

On Sun, Apr 7, 2013 at 8:00 PM, Ƕ [email protected] wrote:

Hi.

I am testing my custom modulation scheme ppm.py. I followed this post
http://lists.gnu.org/archive/html/discuss-gnuradio/2010-12/msg00265.html

to register this modulation into mods/demods. I added a line

import ppm

in my benchmark_tx.py.

I also tried placing the ppm.py file in blks2impl directory. However
neither method worked. The result from “print
digital.modulation_utils.type_1_mods()” did not contain ppm.

Another issue is that I modified digital_constellation.cc, and I called
functions in the modified digital_constellation.cc in my ppm.py. In this
case should I rebuild gnuradio? If not, what should I do?

Any suggestions?
Thanks!

Fei

Hi Fei,

The issue is that in the directory benchmark scripts are in isn’t aware
of your ppm file. You have a few options that you can explore by
searching around for python import path or search path. and doing some
reading. You can take a look in gr-digital/python/init.py to see how
the other mod/demods are imported. Adding a line in that file “from ppm
import *” should make your ppm stuff show up in Python after rebuilding
gnuradio.

And yes, you should rebuild gnuradio. Any time you change C++ source
code you must rebuild it.

-Nathan

Hi Nathan,
Thanks for your reply. I’ll give it a try.
Fei

4

in my benchmark_tx.py.

-Nathan

Hi Nathan,

I’ve made my ppm a usable module in digital after rebuild. Thanks for
your help!

Fei