[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] QPSK basic modulator

From: Karim El Defrawy
Subject: Re: [Discuss-gnuradio] QPSK basic modulator
Date: Wed, 08 Apr 2009 11:55:47 +0100
User-agent: Thunderbird (Windows/20090302)

Jason Uher wrote:
I checked the benchmark_tx.py it adds a preamble and a lot of data before
the actual payload which I don't need.

I assume you are trying to do some BER measurements?  There is an
example called digital-bert that will do that (bert=bit error rate

Actually I am not. I just want to transmit the data using QPSK and capture it by an oscilloscope. I want to see how I can control the frequency offset, phase and amplitude by playing with these parameters at the transmitter and how this will affect the sent signal.

There are small errors introduced by the radio and I want to study those.

If you have some other goal in mind, I would suggest examining the
digital_benchmark_*.py files and extracting the blocks you need into a
new python file that simply modulates and sends (basically skip the
packet_{sink|source}).  Keep in mind that there would be no
synchronization at the receiver with such a setup and that when you
repack the bytes there may be an offset that you have to account for
during processing.

At this point I don't care about demodulation, but you are right. I probably will later.

Thanks a lot Jason. I will start doing that too.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]