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[Discuss-gnuradio] am reception examples
From: |
Matteo Campanella |
Subject: |
[Discuss-gnuradio] am reception examples |
Date: |
Fri, 3 Mar 2006 00:06:01 +0100 |
In some of the examples, I have noticed certain approaches I am not able to
explain on my own, so I am asking for help to the list...I am talking for
example about am_rcv.py - it uses an offset_freq of 30kHz to recalculate the
correct offset afterwards. I have tried modifying the python in order NOT to
use the initial offtset, and everything works correctly - does anybody as an
answer? To make things clearer:
offset_freq = 30e3
# IF_freq = offset_freq - station ;original line
IF_freq = -station ;modified line
and some lines later:
src.set_rx_freq (0, IF_freq)
actual_IF_freq =src.rx_freq(0)
actual_offset = actual_IF_freq + station
Also, as I could notice printing the values returned, it does look like the
usrp cannot be simply put on a frequency with the rx_freq method - the
strategy used in this script is indeed to go as close as possible to the
needed frequency and then use the software dds/fir to do the last
translation of the spectrum.
In another script, usrp_wfm_rcv.pl, another method has been used, the
usrp.tune, that, according to the tests, does not need any successive
adjustment - is there any reason why the am receiver is not written using
this method?
Another doubt is about optfir.low_pass versus gr.firdes.low_pass - from the
tests I have run, the first one is much faster of the second - is there any
reason to use the second instead of the faster optfir?
regards
Matteo
- [Discuss-gnuradio] am reception examples,
Matteo Campanella <=
- Re: [Discuss-gnuradio] am reception examples, Eric Blossom, 2006/03/04
- Re: [Discuss-gnuradio] am reception examples, Matteo Campanella, 2006/03/05
- Re: [Discuss-gnuradio] frequency tuning word quantization, Eric Blossom, 2006/03/05
- Re: [Discuss-gnuradio] frequency tuning word quantization, Martin Dvh, 2006/03/05
- Re: [Discuss-gnuradio] frequency tuning word quantization, David I. Emery, 2006/03/05
- Re: [Discuss-gnuradio] frequency tuning word quantization, Eric Blossom, 2006/03/05
- Re: [Discuss-gnuradio] frequency tuning word quantization, David I. Emery, 2006/03/05
- Re: [Discuss-gnuradio] frequency tuning word quantization, Eric Blossom, 2006/03/07
- Message not available
- Re: [Discuss-gnuradio] frequency tuning word quantization, Eric Blossom, 2006/03/08
- Message not available
- Re: [Discuss-gnuradio] frequency tuning word quantization, Eric Blossom, 2006/03/08