CVSD vocoder

GNU Radio
1

Just an announcement that I’ve just merged in a CVSD vocoder. You can
use it through the wrapper blocks blks.cvsd_encode and blks.cvsd_decode.

I want to give a big thanks to Mark Silvius, Alex Y., and Chen C.,
three graduate students I work with who actually put the system
together. I just helped import it into GNU Radio blocks.

Tom

2

Tom R. wrote:

Just an announcement that I’ve just merged in a CVSD vocoder. You can
use it through the wrapper blocks blks.cvsd_encode and blks.cvsd_decode.

Nice work all around.

It does need to be said, though. Do you know just how many people
have been made miserable by that %$#@! format?
If you did, you might not have been so quick to unleash it once
more on an unsuspecting world.

Regards
Frank

3

On Sun, Apr 08, 2007 at 09:59:21AM +0930, Berndt Josef W. wrote:

G’day,

I’ve found various implementations of SSB demodulators but no modulators? Has
anyone written or seen an implementation of a SSB modulator?

cheerio Berndt

Here you go:

real_sig = # at 250k samples/sec
f2c = gr.float_to_complex()
u = usrp.sink_c(0, interp_rate=512)
fg.connect(real_sig, f2c, u)

Eric

4

G’day,

I’ve found various implementations of SSB demodulators but no
modulators? Has
anyone written or seen an implementation of a SSB modulator?

cheerio Berndt

5

On Sat, Apr 07, 2007 at 06:38:09PM -0700, Matt E. wrote:

hilbert transform to create the imaginary part. Hilbert transforms are
in firdes code already.

Thanks!

Eric

6

Eric B. wrote:

Here you go:

real_sig = # at 250k samples/sec
f2c = gr.float_to_complex()
u = usrp.sink_c(0, interp_rate=512)
fg.connect(real_sig, f2c, u)

Eric

Actually, that will get you a double sideband signal. You need to use a
hilbert transform to create the imaginary part. Hilbert transforms are
in firdes code already.

Matt