Possiblity of Modulation without the usrp? PSK modulator?


#1

Greetings,
I’m wondering if you all could tell me if it is possible to set up and
modulate a signal without the usrp? If so how do you insert the
carrier?
For a BPSK siganl do you just multiply carrier by the modulated signal?
I
also notice that gnuradio did at one time have a PSK modulator but it is
no
longer available…what took it’s place? Without a PSK modulator,
how do
you modulate signals like BPSK, QPSK, 8PSK.?

Thanks,
Jody


#2

On Tue, Mar 10, 2009 at 09:31:57AM -0400, w w wrote:

Greetings,
I’m wondering if you all could tell me if it is possible to set up and
modulate a signal without the usrp? If so how do you insert the carrier?
For a BPSK siganl do you just multiply carrier by the modulated signal? I
also notice that gnuradio did at one time have a PSK modulator but it is no
longer available…what took it’s place? Without a PSK modulator, how do
you modulate signals like BPSK, QPSK, 8PSK.?

Please take a look at *psk.py in
gnuradio-core/src/python/gnuradio/blks2impl

Each file contains both the modulator and demodulator.

Eric


#3

Yufeng,
Yes, I’m still looking at setting up BPSK, QPSK and 8PSK. I was however
able to TX and RX DPSK and GMSK without the USRP.

However, I was wondering if you had the history of TX of PSK with
GNUradio. In the past there was a block named BPSK.py but now it is
not
there. It seemed very similar to the Digital BERT example using a
costas
loop and MM clock recovery. Then there is a MPSK receiver that was added
there after. It seemed to me like the natural progression was to add a
MPSK transmitter or better yet hold to the schema with DPSK,GMSK and QAM
and
have a MPSK Mod and a MPSK Demod. Do you know why BPSK.py dissappeared
and
it was not replaced with a MPSK transmitter or MPSK Mod?

I took a look at PSK.py and got confused because it seemed to only deal
with
Gray coding only…what am I missing?

Cheers,
Jody