2007, Matt Ettus wrote:
Anastasopoulos Achilleas wrote:
Hi,
I noticed that the Gaussian pulse is convolved with a rectangular window
in the GMSK modulator. Why is that so?
The pulse is convolved with a rectangular window because the incoming data is
not.
For example, if you wanted to send
Hi,
I noticed that the Gaussian pulse is convolved with a rectangular window
in the GMSK modulator. Why is that so?
Thanks
Achilleas
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Hi,
I am running a simple graph in GRC-0.65 with complex USRP as source
(with TVRX at the B side) and a complex FFT as a sink.
What I see is not expected: I see the FFT of a real signal
(symmetric around 0).
When I run the python example usrp_fft.py I get
the expected result.
./usrp_fft.py -RB -
Dan,
thanks for the info you provided; it was ver helpful!
I think I got the basic understanding of the message_source/sink.
I wrote my first toy code based on this:
The Tx queues 100 packets and the Rx waits until
it receives everything (broken into different number of packets)
The Rx does
Hi,
I am trying to understand how the message source works
and how I can use it from within my python code.
So I wrote a simple script with a message source and a null sink.
I wanted the following behavior:
every time I press a button on my keybord to send a constant message in
the queue and ver
I am running it on a Fedora Core 5.
This was the latest trunk.
Thanks
Achilleas
On Wed, 21 Feb 2007, Eric Blossom wrote:
On Wed, Feb 21, 2007 at 05:59:59PM -0500, Achilleas Anastasopoulos wrote:
Hi there,
I am trying to install gnuradio in an environment where I do not have
root priviledges
Hi there,
I am trying to install gnuradio in an environment where I do not have
root priviledges, so
everything has to go in my user space.
I went through the regular cycle using the ./configure
--prefix=/n/wellington/x/anastas/local
so that everything is installed under my ~/local director
Brian,
Yes it can!
You need to set a decision delay D and then it would operate in a
fixed-delay mode, ie, it would spit out a decision at every time instance
with a delay of D compared to the input sample.
The survivor matrix (of size DxS) will need to be updated at every
time instance in ord
Tim,
If the number of additional bits is not significantly
bigger than the fixed packet length (in your example 200),
then you can instantiate the VA with the MAXIMUM expected
length (eg, K=200+10). For this to work you have to
1) put a block before it that appends 0's (or something else)
in pack
Josh,
I imported some blocks from gr-trellis on GRC.
However there seems to be a problem.
The graph does not run and exits with something like:
...
flow graph save
SRC_DIR: /net/ernesto/home/anastas/grc_mine/src
DATA_DIR: /net/ernesto/home/anastas/grc_mine/data
FILE_PATH: /n/ernesto/home/anast
by a
drift/jitter of the ADC on the order of 25ppm
Is this within the drift/jitter specs of the ADC?
Thanks
Achilleas
On Tue, 23 Jan 2007, Anastasopoulos Achilleas wrote:
Thanks for pointing out all theses raw files
for testing the usrp_tv_rcv.py application.
I tried a couple of them and
Thanks for pointing out all theses raw files
for testing the usrp_tv_rcv.py application.
I tried a couple of them and they work fine.
Now I have the following question:
Why is it that the video shown on sdl moving
slowly to the right?
The fact that there is no vertical or horizontal
synchroniz
Hi,
I have installed FC5 on my PC and built gnuradio.
Everything seems to work fine.
However I get the following warnings
when I run the usrp examples.
where are they coming from?
Thanks
Achilleas
$ ./usrp_wfm_rcv.py
Using RX d'board B: TV Rx
gr_fir_ccf: using SSE
gr_fir_fff: using SSE
FYI
Josh,
I commented out the part you suggested and then it gave me the following
message:
---
Traceback (most recent call last):
File "./Main.py", line 7, in ?
import ActionHandler
File "/home/anastas/grc_0.50/src/ActionHandler.py", line 14, in ?
import Dialogs
File "/home/
Josh,
I tried your application on Fedora Core 3.
I get the following error.
Not sure if it is something easy to fix though.
Any suggestions are welcome...
Achilleas
PS: the screenshots look great!
---
Traceback (most recent call last):
File "./Main.py", line 7, in ?
import A
For an input sequence of length N and a filter with L taps
the output sequence should have N + L-1 samples.
It seems that the GnuRadio implementation produces exactly N
samples, ie, it does not generate the L-1 tail samples.
I guess the reason is that there is no way of knowing
when the input seq
No need to re-implement the Viterbi algorithm on your own.
It is implemented in a very general form in gr-trellis :-)
See examples of how to initialize it in
gnuradio-examples/python/channel-coding/
Achilleas
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From your reply I think you are referring to problem 1B.
I am indeed.
This is great. I did not know you had checked in the siso code in
gr_trellis. I am now more anxious to go study it more carefully. I am glad
I commented.
As a side note, this algorithm is the basis of all "turbo-l
idimensional
modulations, whats the best way to go about it? Is there any published
literature on this that I could base it on?
Kind Regards,
Toby
Anastasopoulos Achilleas wrote:
Oliver,
You are right:
Trellis implementation supports multi-dimensional constellations etc
(through the metric ca
Oliver,
You are right:
Trellis implementation supports multi-dimensional constellations etc
(through the metric calculation block abstraction, etc), however,
in the examples and the supporting fsm_utils.py files
I have not included support for GMSK, and the automatic
generation of lookup tables f
Guys, I remember someone gave me an answer to
a similar question in the past regarding the Digital upconverter
in the TX path that is implemented inside the ADC chip.
I have a similar question for the DDC in the RX path which is implemented
in the FPGA:
On the receiver path, the DDCs perform com
Guys,
How are the 4 complex streams out of the 4 DDCs multiplexed into the USB
port?
If the 4 ADCs sample at 64MSps, and each of the DDC's is downsampling by
N,
then there are 4 complex streams of 64/N MSps waiting to be transfered
through the USB port.
How do we control (if we can control) which
Everything works fine with gnuradio and USRP when
I use it a s root.
When I tried to use it as a regular user,
when I run
./tvrx_wfm_rcv_gui.py 93.1
I get error messages that look like
the obes below.
Is there a problem with permissions, etc that can be easily fixed?
Thanks
Achilleas
>> Are the connections from the daughterboards to the
>> ADC's
>> hardwired in the USRP the way it is shown in the
>> figure,
>> ie, RX-A to ADC-0, RX-B to ADC-1 and the IF output
>> of the
>> TV-RX to both ADC-2 and ADC-3 ?
>I think this is the default wiring:
>RxA (Jumper 19 )-ADC 0
>RxB (Jumpe
I apologize for the confusion:
I meant the file
tvrx_wfm_rcv_gui.py
Achilleas
> According to usrp_wfm_gui.py the correct MUX seting
> for listening to
> FM is0x f0 f0 f0 f2.
Could you please point me to this file ? Im not able
to locate it in my code. Or did you mean
wfm_rcv_gui.py ?
Jav
Dear all,
I guess I should have spent more time experimenting and
studying the examples before asking these questions.
In any case, I have resolved both issues:
As it turns out the ADC's (I guess due to some
hardware mismathces etc) may add a DC term at the output.
This offset can be eliminated e
Now that I understand how the basic Tx and usrp_siggen works,
I am trying to get a handle on the basic Rx and the usrp_fft.py script.
Here are a couple of observations/questions:
1) If nothing is connected to the basic Rx I get a strong DC term
on the fft display. Where is this coming from? Also
Let me make sure I understand this:
What exactly is happening in the FPGA on the Tx side?
My guess is that there a CIC interpolator that takes
the USB complex samples and interpolates them to a
complex stream with 32Msps, ie, 64Msps (real).
Is this accurate?
Now assuming that {z_k} represents t
Is this comment relevant for the Tx only
or for both TX and Rx ?
> Just one minor correction from what I said before. The way you show the
> multipliers and the NCO is not quite correct. It is doing a full
> complex
> multiplication. The CORDIC does the NCO and the multiplication
> together.
>
I hooked up an analog osciloscope on the Basic Tx daughterboard and tested
the usrp_siggen.py. It seems to work!
A couple of questions:
1) what are the units of amplitude? (the default is 16e3)
2) why does the amplitude change if I change the frequency?
I guess it is related to a constant mult
As I mentioned in a previous email,
using the "tv_wfm_rcv.py" from the latest tarballs
I get an error when decim=250 saying
usrp_standard_rx::set_decim_rate: WARNING rates > 128 result in incorrect
gain.
Now I changed the decimation to
decim = 100
(which is a "valid" decimation rate according to
Dear all,
After updating my FC3 and reinstalling the
latest tarballs I think I have a distribution with a
working USRP module (with Basic Rx,Tx and 4937 daughterboards).
Thanks for the comments/suggestions.
However there are still some issues that I have not resolved:
benchmark_usb.py works fine
I know this is not the right list for this, but
I wonder if anyone else had the same experience.
In python (ver 2.3) when I do
import wx
it loads the package without complaining.
Then when I do
help(wx)
it gives error messages and a segmentaion fault.
All errors relate to Glib and Gtk.
Has a
Dear all,
I received the USRP, followed the WiKi instruction and
it seems to be working since I get meaningful result when I run
test_usrp_standard_tx and test_usrp_standard_rx.
I have also updated my gnuradio installation using
tarballs 2.5
However I have problems running any of the python
scri
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