[Discuss-gnuradio] Matt USRP Family Document
Hi, I found this document written by Matt about USRP2: http://bwrc.eecs.berkeley.edu/Research/Cognitive/usrp-family-09-open.pdf Best Regards, Firas -- View this message in context: http://www.nabble.com/Matt-USRP-Family-Document-tp24367955p24367955.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] CUDA-Enabled GNURadio gr_benchmark10 possible improvements
any help? 2009/7/2 Yu-Hua Yang flagm...@gmail.com -- Forwarded message -- From: Yu-Hua Yang flagm...@gmail.com Date: 2009/7/2 Subject: Re: [Discuss-gnuradio] CUDA-Enabled GNURadio gr_benchmark10 possible improvements To: Martin DvH gnuradiom...@olifantasia.com Cc: discuss-gnuradio discuss-gnuradio@gnu.org Thanks Martin, for your generous effort to help me. It appears only one time so I think I am in the clear. I decided to abandon and comment out all the cuda.multiply_const_ff function calls and concentrate on cuda.fir_filter_fff as suggested. Things I got questions/concerns 1. I increased output_multiple by doing options.output_multiple = xxx and this has no effect on the computing time of either CUDA or CPU. Did I do something wrong? 2. I increased the taps by doing taps = range(1,256) and also increasing number of blocks of fir_filter in the code and voila, I am now able to get CUDA to be faster than just CPU. However, if I implement something like taps = range(1,512) the CUDA part would be extremely slow (~20 seconds) while the CPU is still cool (~ 2 sec). Why? But this maybe related to what you were saying about max number of taps...although why is CPU able to still compute? 3. I had to increase the number of fir_filter blocks to 14 blocks before I can start seeing CUDA out-perform CPU. Experimentally its fine, I achieved my objective, but how is this increased computation justified in a normal GNURadio operation? I mean, when would a normal GNURadio operation require a chain of 14 fir_filters? I guess this is going beyond just benchmarking and asking where else can I take advantage of CUDA's computation power in GNURadio in a normal operation? 4. Looking at cuda_fir_fff_7_kernel, which I believe is the core of cuda_fir_filter, it seems you are using shared memory right? Just making sure we are not using global or local memory which would disastrously slow down the CUDA computations. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Sound input using mic / line in problem
On Fri, Jul 3, 2009 at 1:05 PM, John Gilmore g...@toad.com wrote: gr-audio-oss and gr-audio-jack. The sound module being used is snd_hda_intel. In my experience, there seem to be endless permutations of problems with snd_hda_intel (HD Audio). Even in newer Linux releases like Ubuntu 9.04. I don't think I have a single machine on which snd_hda_intel is trouble-free -- including an HP Athlon64 desktop, a Dell Atom netbook, and an Acer Atom netbook. (which may or may not have anything to do with your problem.) John Thanks for the pointer. Adding a line in /etc/modprobe.d/alsa-base which specified the model of my computer helped (Dell Precision), more details here https://help.ubuntu.com/community/HdaIntelSoundHowto. However, the inputs in ALSA don't get correctly mapped to the actual physical inputs. For eg, the Front Mic on ALSA was actually the rear line-in. This only solved the problem of being able to get the example program running without any device busy errors or lockups. To be able to actually record sound, I had to install jack and play around with the settings for a bit. When using gnuradio I also added audio_module = audio_jack to the gnuradio config.conf file. Karthik ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] (no subject)
I haven't receive my USRP yet so i am trying to make some simple, USRP independenent applications. I want to implment FSK modulator by transfering a signal between two laptops using the sound card ,the problem is i get syntax error when using the You'd probably be better off using the gr.channel_model on a single PC, the sound card method seems to introduce unnecessary complication. Look at the benchmark_loopback.py example in the examples/digital/ folder for an example on how to use it to test your transmit and receive flowgraphs. Jason ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] OFDM benchmark - premature termination
Katy Qian wrote:
Hi,
For the majority of my tests (ex. below), with benchmark_ofdm_*, the
receiver terminates prematurely with:
...
ok: True pktno: 7501 n_rcvd: 4537n_right: 4263
ok: True pktno: 7502 n_rcvd: 4538n_right: 4264
ok: True pktno: 7503 n_rcvd: 4539n_right: 4265
Exception in thread Thread-1:
Traceback (most recent call last):
File /usr/local/lib/python2.4/site-packages/gnuradio/gr/gr_threading_24.py,
line 446, in __bootstrap
self.run()
File /usr/local/lib/python2.4/site-packages/gnuradio/blks2impl/ofdm.py,
line 294, in run
self.callback(ok, payload)
File ./benchmark_ofdm_rx.py, line 168, in rx_callback
(pktno,) = struct.unpack('!H', payload[0:2])
error: unpack str size does not match format
uOuOuOuOuOuO
...
It seems a certain combination of fftlength, occupied tones, and cp
length allows the program to run to completion (FFT/OT/CP = 64/28/54
and 40/20/32 works but 256/160/128 ends early). Does anyone know the
magic behind these sets of values, or can explain something I have
overlooked?
This is an error that occurs when the packet is corrupted in a way that
ends up with an empty payload, usually due to a bad value for the packet
length in the header.
Also, is there a way to control / define exactly which subcarriers are
being used to transmit the data?
No. You have to hack the C++ code in gr_ofdm_mapper. Others have been
looking to do the same thing, but I'm not sure how far they have gotten.
Any help is appreciated, thank you in advance.
Katy
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Re: [Discuss-gnuradio] Programming USRP as a relay node
On Sat, 2009-07-04 at 14:15 +0300, Tasos Kyrillidis wrote: Hello everyone, I am a postgraduate student at Technical University of Crete, Chania and i am currently working on a project with USRPs. Part of our project is to communicate with a relay node. But this relay node is a little bit slow, because there is data transfer from USRP to PC and then from PC to USRP. So, there is an idea to program the FPGA of USRP as a relay without any communication between PC and USRP - the relay node just detects packets and retransmit them without any further processing. 1. One idea is to program the FPGA to include a packet detector and a raised cosine filter. But I read somewhere that the default FPGA has only 5% available resources and i am wondering if these resources are enough for a packet detector and a raised cosine filter? You can free up resources by reducing the number of channels. In your case, only one RX and one TX channel in stead of two. You can also replace the halfband filter with a raised cosine filter. (Note, you can only use a limited number of taps, depending on the decimation factor) A simple signal level detector should be doable. For a packet detector and best S/N ratio you should completely demodulate the packets and remodulate them (regenerate the signal) This will be quite complicated though and possibly not fit in the FPGA. When you use a USRP2 you have much more room in the FPGA. Implementing a complete receiver, packet detector and transmitter will certainly fit, but it will still be a complicated design. Greetings, Martin 2. In case there are enough resources (in some way), could anyone estimate how difficult would be to implement it? Has the current configuration to be changed a lot or including the appropriate modules is enough? I know that my questions are kind of abstract but i couldnt express them differently Thanks anyway Tasos Kyrillidis __ What can you do with the new Windows Live? Find out ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Multichannel problem
Hello everyone, I have posted a similar question before but didnt get too much attention thats why I am posting this question with hopes that I will get some response this time because I have tried to make the question simpler. In one line the problem is I am so far unable to configure 2 RX channels with RFX2400+USRP1. I have read mostly related mails on this forum and GNURadio examples as well, I am doing exactly what is mentioned in all these but still no success. To understand the problem please read the following. I implemented spectrum sensing, first with single RX channel (it works), and then I modified it for 2 RX channels and here I have problems. I first tried sensing with a single channel (This code is well known and some where available on this forum or GNURadio examples), it is working fine. In this code I simply display the maximum value of each FFT scan. When I have some data source at the frequency which I have set (2.41GHz at the moment) then I can easily see it. This code is attached as sensing_single_RX_channel.py at the end Then I changed this code for two RX channels, one one path I kept the same graph for sensing and the output of other graph is sent to a file. If I forget the output of file for the time being and focus on other leg of the graph i.e. spectrum sensing even then my sensed signal is too weak. For example if with one RX version I was receiving value '75' then now I am receiving only '10'!!! This 2 RX channel version is also attached as sensing_2_RX_channel.py Its very easy to run these files on your system. Can some one help me to find what is the problem. Thanks http://www.nabble.com/file/p24374390/sensing_single_RX_channel.py sensing_single_RX_channel.py http://www.nabble.com/file/p24374390/sensing_2_RX_channel.py sensing_2_RX_channel.py -- View this message in context: http://www.nabble.com/Multichannel-problem-tp24374390p24374390.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Suggestion to Improve Some Digital Modulations Reception
Hi, I never used Gnuradio packets transmission blocks and even don't know how the digital benchmark_?X.py work. But, today when I was explaining GNURadio for some friends, I noticed that some digital modulations (for example GMSK) reception can be improved by using a scrambling engine which is something I used before many years ago to improve data reception circuitry performance. The problem is raised when the digital source is producing a long sequence of 0's or 1's. This will make the regeneration process more difficult at the receiver. To solve this problem, I used 8 bit shift register with its input derived from XOR which is fed from the source digital input and from a second XOR. The second XOR takes its input from the 4th and 8th shift register bits. Implementing this circuit as a GR block is easy and helpful. Best regards, Firas -- View this message in context: http://www.nabble.com/Suggestion-to-Improve-Some-Digital-Modulations-Reception-tp24375263p24375263.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Suggestion to Improve Some Digital Modulations Reception
On Tue, Jul 7, 2009 at 08:14, Firas A.firasmail2...@yahoo.com wrote: ...some digital modulations (for example GMSK) reception can be improved by using a scrambling engine which is something I used before many years ago to improve data reception circuitry performance. Pseudo-randomizing bit sequences to prevent long runs is a standard radio technique, as you mention. GNU Radio has gr.scrambler() and gr.descrambler() blocks to do this. The first takes unpacked bits in and feeds them through a configurable LFSR; the second undoes this operation to return the original bits. See the 'digital-bert' example for how this is used to test the bit error rate of a BPSK channel. In the example digital packet radio application, we instead use a whitener that has a pre-generated sequence of bits that we XOR the payload with. Johnathan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Suggestion to Improve Some Digital Modulations Reception
--- On Tue, 7/7/09, Johnathan Corgan jcor...@corganenterprises.com wrote: GNU Radio has gr.scrambler() and gr.descrambler() blocks to do this. In the example digital packet radio application, we instead use a whitener that has a pre-generated sequence of bits that we XOR the payload with. Johnathan AhaGNURadio is great. Best Regards, Firas ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Question about the bandwidth of OFDM
Hi, I am trying to use benchmark_ofdm_tx.py and benchmark_ofdm_rx.py to test the OFDM communication between two usrp nodes. While the transmitter is sending data, I use a sprctrum analyzer to observe the spectrum, and find the signal bandwidth far beyond my calculation, which is 330kHz around with the --fft-length/--occupied-tones=512/256. With my calculation, the sampling rate of DAC is 128Msamples/second, and each sample has 14bits, so the with the interpolation setting to default(256) the bandwidth of signal should be 128M*14/256=7MHz. Is that correct? If not could anyone tell me how to calculate in a right way? Another problem is when I change the occupied-tones to 64, the bandwidth of signal will drop to 180kHz. I think the bandwidth of signal should be fixed to some bandwidth if you don't change the interpolation, and the occupied-tones should only affect the bandwidth of each sub-carrier. Is that a correct understanding? I also tried changing packet size, seemed it also affected the bandwidth of ofdm signal. I am really confused. By the way, the bandwidth I mentioned above with out specified are all null to null bandwidth. Thanks, Best regards, Yan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] VRT and UDP
What is the situation with VRT and UDP? Has what's going into the VRT context packets been finalized? If so, where should I look for this information? I've been looking in Eric Blossom's branch, it looks like he is doing most of the VRT development, is this right? Who is doing the UDP development and how far along is it? Thanks Devin ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] propagation study
This sort of thing is heavily dependent upon the transmission environment. I wouldn't think it could be generalized. Jordan On Mon, Jul 6, 2009 at 11:44 AM, adib_sairi adib_sa...@yahoo.com wrote: Jordan J Riggs wrote: What do you mean by signal propagation study? Can you be more specific? Jordan On Mon, Jul 6, 2009 at 1:19 AM, adib_sairi adib_sa...@yahoo.com wrote: Hi everyone, Is there any signal propagation study being done on USRP and GNU Radio SDR? is there any graph, data or analysis? what is the minimum power (dBm) that the receiver require to receive the data correctly? if there is non, i am planing to do experiment on all this issue.. thank you. Adib I mean a study of USRP Radio propagation either LOS or NLOS.. any graph that show the radio propagation of the USRP or is there any work related to this? thank Jordan for the reply. Adib -- View this message in context: http://www.nabble.com/propagation-study-tp24350842p24359843.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] VRT and UDP
On Tue, Jul 07, 2009 at 01:28:01PM -0400, devin kelly wrote: What is the situation with VRT and UDP? We've got UDP and the IF-Data working on an experimental platform, but it hasn't been ported to the USRP2 yet. When everything is fully wrung out on the experimental platform, we'll back-port it to the USRP2. That's unlikely to take place before September. Has what's going into the VRT context packets been finalized? No. If so, where should I look for this information? I've been looking in Eric Blossom's branch, it looks like he is doing most of the VRT development, is this right? Yes. Who is doing the UDP development and how far along is it? See above. Eric ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Audio Sample rate problem
my audio sampling rate is 48000 not 32000 so all the the gnu examples that output an audio dont work and due to this 48000 i cant configure the decimation and interpolation to be even integers as required so is there away to change sampling rate of my audio card to 32000 i am using Dell Inspiron 1525 with ubuntu 9.04 with the latest version of GNU and my USRP is rev 4.2 Please i need help ASAP Thanx ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Permissions problem installing packages on Cygwin:
Dear All:
During trying to install GNURADIO on a windows machine I am sure that every
one runs into the following link:
http://gnuradio.org/trac/wiki/WindowsTips
I was having problems with the permissions on my Cygwin installation. The
document above mentions about the ownership of two directories
/usr/local/{lib,bin}.
I was trying to install gr on windows VISTA. And even though I had the
ownership of the above mentioned directories I still didn't have Permission
to the folders.
*For Windows Vista:*
Make sure the *User Account Control* is turned OFF. That blocks the
permission to the folders, even though you have the ownership.
Wanted to share this with the group.
Thank you loads.
Regards,
Shabbir
--
Shabbir Ahmed
PhD. Student
Centre for Telecommunications and Microelectronics
Victoria University
Email: shabbir.ah...@live.vu.edu.au
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Re: [Discuss-gnuradio] Audio Sample rate problem
On Tue, Jul 7, 2009 at 11:20 PM, Abdalla Sokarabdallaso...@yahoo.com wrote: thanx very much this way really worx and wonderfully too --- On Wed, 7/8/09, davek davidki...@gmail.com wrote: From: davek davidki...@gmail.com Subject: Re: [Discuss-gnuradio] Audio Sample rate problem To: Abdalla Sokar abdallaso...@yahoo.com Date: Wednesday, July 8, 2009, 5:14 AM i dont know much about this so it might be wrong but if you cant figure it out you could put a fractional interpolation filter before your audio block set to 2/3 On Tue, Jul 7, 2009 at 8:58 PM, Abdalla Sokarabdallaso...@yahoo.com wrote: my audio sampling rate is 48000 not 32000 so all the the gnu examples that output an audio dont work and due to this 48000 i cant configure the decimation and interpolation to be even integers as required so is there away to change sampling rate of my audio card to 32000 i am using Dell Inspiron 1525 with ubuntu 9.04 with the latest version of GNU and my USRP is rev 4.2 Please i need help ASAP Thanx ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Permissions problem installing packages on Cygwin:
Hi, --- On Wed, 7/8/09, Shabbir Ahmed shabbirahmed...@gmail.com wrote: For Windows Vista: Make sure the User Account Control is turned OFF. That blocks the permission to the folders, even though you have the ownership. Wanted to share this with the group. Thank you loads. Regards, Shabbir Thank you for sharing this tip. You may add this tip to gnuradio wiki windows instalation tips. login using: username : guest password : gnuradio Best Regards, Firas ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
