RE: [Discuss-gnuradio] BBN 802.11b questions
Hi Douglas, Douglas Geiger wrote: > As I recall, the transmit functionality of the original BBN code was > not standards compliant: due to the limited bandwidth of the USRP1 it > did not actually do DSSS (or CCK, etc.) - it created the frame, and used > DBSK (and possibly DQPSK) - but I don't think it did any sort of spreading. > Doug Actually I think that spreading IS implemented (see barker sequence). As far as I remember, the legacy IEEE802.11 at 1 Mbps uses DBPSK and barker sequence. Any 802.11b/g card should be able to receive that. If this is correct, I believe that, by putting a wifi-card in monitor/passive mode, a frame correctly transmitted from the USRP will be decoded by the card. If your card allows you to disable CRC check at MAC layer, then you should see the frame also on wireshark (as a malformed packet)... I'll let you know if it works out! In the meanwhile, if you find errors in my thoughts, well tell me and I save time for something more useful! ;-) bye, Dan :-) ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] TVRX gain troubles
Andrew Lutomirski wrote: Hi- I'm having trouble with the gain control on a TVRX (actually, on a whole bunch of TVRX's). There are two problems: 1. The effect of the gain setting is far from linear. I measured this with the attached program, at 1 dB increments of requested gain, with antennas (with LNAs) attached to both channels. (I'm not completely sure I have the full scale right, but that's just an offset.) I get essentially identical results using usrp_rx_cfile.py and a little Python script to do the same calculation (also attached). The gain vs. gain setting is always going to be somewhat nonlinear, as you have seen. There are 3 stages of gain control -- RF, IF, and PGA. The only one you can expect to be perfectly linear is the PGA (the last 20 dB). The reason you see the first two plateaus in the gain curve is that at the high end of the range of each of those gain settings, the gain amps become nonlinear is twofold -- First, the gain range becomes more nonlinear near the top of each variable gain amp. You could compensate for this in the gain setting function in the daughterboard code if you like, by reducing the amount of gain we try to get from each stage. Second, if your signal is strong enough, it will cause saturation in the frontend. The formula we use in the daughterboard code for the TVRX is by no means optimal. What it does is first add gain to the RF, until that is maxed out. Once that happens, it adds gain to the IF. Once that is maxed out, it puts the remaining gain in the PGA. Every application will have different requirements. For example, if there is a strong inband interferer, you will need to reduce the gain. You might also want to distribute the gain differently, instead of putting it all up front. 2. The system acts like there's some kind of automatic gain control. My setup is an antenna (with built-in LNA), connected through a combiner, to the USRP. On the other input to the combiner is a signal generator. The entire setup is duplicated on sides A and B. I did two runs. First, I had the signal generator on and the antenna connected. Then I replaced the antenna with a terminator and left the signal generator on. (The USRP was tuned to 106MHz and the signal was a sine wave at 106.25MHz.) The power I see in MATLAB at 0.25MHz from center is dramatically (12 dB) less with the antenna connected. > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio There is nothing automatic unless you implement it. What you are seeing is compression of your signal from strong nearby stations when you attach the antenna. Since you are in the FM band, it is likely that one or more very strong stations are nearby. Matt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] TVRX gain troubles
Hi-
I'm having trouble with the gain control on a TVRX (actually, on a
whole bunch of TVRX's). There are two problems:
1. The effect of the gain setting is far from linear. I measured this
with the attached program, at 1 dB increments of requested gain, with
antennas (with LNAs) attached to both channels. (I'm not completely
sure I have the full scale right, but that's just an offset.) I get
essentially identical results using usrp_rx_cfile.py and a little
Python script to do the same calculation (also attached).
2. The system acts like there's some kind of automatic gain control.
My setup is an antenna (with built-in LNA), connected through a
combiner, to the USRP. On the other input to the combiner is a signal
generator. The entire setup is duplicated on sides A and B. I did
two runs. First, I had the signal generator on and the antenna
connected. Then I replaced the antenna with a terminator and left the
signal generator on. (The USRP was tuned to 106MHz and the signal was
a sine wave at 106.25MHz.) The power I see in MATLAB at 0.25MHz from
center is dramatically (12 dB) less with the antenna connected.
Any ideas what's going on?
This occurs with gnuradio trunk r10579. I'm updating now and will try
again with a newer trunk shortly.
Thanks,
Andy
<>/* -*- c++ -*- */
/*
* Copyright 2003,2006,2008 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* GNU Radio is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "usrp_tree_config.h"
#include
#include
#include
#include
#include /* needed for usb functions */
#include
#include
#include
#include
#include "usrp_standard.h"
#include "usrp_bytesex.h"
#include "fpga_regs_common.h"
#include "fpga_regs_standard.h"
#ifdef HAVE_SCHED_H
#include
#endif
using std::cerr;
using std::endl;
char *prog_name;
static bool test_input (usrp_standard_rx_sptr urx, int max_bytes, FILE *fp);
static void
set_progname (char *path)
{
char *p = strrchr (path, '/');
if (p != 0)
prog_name = p+1;
else
prog_name = path;
}
static void
usage ()
{
fprintf (stderr, "usage: %s [-f] [-v] [-l] [-c] [-D ] [-F freq] [-o output_file]\n", prog_name);
fprintf (stderr, " [-f] loop forever\n");
fprintf (stderr, " [-M] how many Megabytes to transfer (default 128)\n");
fprintf (stderr, " [-v] verbose\n");
fprintf (stderr, " [-l] digital loopback in FPGA\n");
fprintf (stderr, " [-c] counting in FPGA\n");
fprintf (stderr, " [-p] output DDC phase\n");
fprintf (stderr, " [-S] use external synchronization\n");
// fprintf (stderr, " [-8] 8-bit samples across USB\n");
fprintf (stderr, " [-B ] set fast usb block_size\n");
fprintf (stderr, " [-N ] set fast usb nblocks\n");
#ifdef HAVE_SCHED_H
fprintf (stderr, " [-R] set real time scheduling: SCHED_FIFO; pri = midpoint\n");
#endif
exit (1);
}
static void
die (const char *msg)
{
fprintf (stderr, "die: %s: %s\n", prog_name, msg);
exit (1);
}
void show_db_info(usrp_standard_rx_sptr urx, int which)
{
cerr << "Daughterboard " << which << ":\n";
db_base_sptr db = urx->db()[which][0];
if (!db) {
cerr << " None found\n";
return;
}
cerr << " Daughterboard is a " << db->name() << endl;
cerr << " Gain range is " << db->gain_min() << " - " << db->gain_max()
<< " with " << db->gain_db_per_step() << "dB per step.\n";
fprintf(stderr, " Freq range is %.2f - %.2f MHz.\n",
db->freq_min() * 1e-6, db->freq_max() * 1e-6);
cerr << " Device is " << (db->is_quadrature() ? "" : "not ")
<< "quadrature.\n";
cerr << " Spectrum is " << (db->spectrum_inverted() ? "" : "not ")
<< "inverted.\n";
}
void tune_one_channel(usrp_standard_rx_sptr urx, int which, double center_freq)
{
db_base_sptr db = urx->db()[which][0];
// The "obvious" way is db->set_freq(center_freq),
// but that ends up with a huge offset because the baseband
// is probably not DC. So we use the magic helper, which does
// further processing in the FPGA.
// A future incarnation might want to skip the latter
// step and do it in software for added control, which is problematic
// due to bandwidth issues.
usrp_tune_result result;
if (!urx->tune(which, db, center_freq, &result))
die("Tuning failed");
fprintf(stderr, "Tune request for channel %d to %.6lfMHz:\n",
which, center_freq *
Re: [Discuss-gnuradio] Problems with grc
lxml checking for xdg-mime... true checking for Python >= 2.5... yes checking for Python Cheetah templates >= 2.0.0... yes checking for Python lxml wrappers >= 2.0.0... no checking for Python gtk wrappers >= 2.10.0... yes* configure: error: Component grc has errors; stopping.* Can someone say me where is the problem and wich is the dependecy that I have missed. ___ 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] Problems with grc
On Tue, Apr 7, 2009 at 4:22 PM, Pablo Mendoza wrote: > Hi! > I am trying to install the gnuradio in ubuntu 8.04, but i can't build grc > application. when I use ./configure --with-boost=$BOOST_PREFIX --enable-grc > the system return the following: > > ... > Component gnuradio-examples passed configuration checks; building. > checking for xdg-mime... true > checking for Python >= 2.5... yes > checking for Python Cheetah templates >= 2.0.0... yes > checking for Python lxml wrappers >= 2.0.0... no > checking for Python gtk wrappers >= 2.10.0... yes > configure: error: Component grc has errors; stopping. > > Can someone say me where is the problem and wich is the dependecy that I > have missed. According to that, Python lxml wrappers is either not found or too old. But I'm not an expert on GRC and if it truly is a requirement or not. Brian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Problems with grc
Hi! I am trying to install the gnuradio in ubuntu 8.04, but i can't build grc application. when I use ./configure --with-boost=$BOOST_PREFIX --enable-grc the system return the following: checking build system type... i686-pc-linux-gnu checking host system type... i686-pc-linux-gnu checking target system type... i686-pc-linux-gnu checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for a thread-safe mkdir -p... /bin/mkdir -p checking for gawk... gawk checking whether make sets $(MAKE)... yes checking for style of include used by make... GNU checking for gcc... gcc checking for C compiler default output file name... a.out checking whether the C compiler works... yes checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking dependency style of gcc... gcc3 checking how to run the C preprocessor... gcc -E checking for grep that handles long lines and -e... /bin/grep checking for egrep... /bin/grep -E checking for AIX... no checking for library containing strerror... none required checking for ANSI C header files... yes checking for g++... g++ checking whether we are using the GNU C++ compiler... yes checking whether g++ accepts -g... yes checking dependency style of g++... gcc3 checking how to run the C++ preprocessor... g++ -E checking whether C++ has std::isnan... yes checking gr_libdir_suffix... checking whether to append 64 to libdir... no checking whether user wants gprof... no checking whether user wants prof... no checking dependency style of gcc... gcc3 checking whether ln -s works... yes checking whether make sets $(MAKE)... (cached) yes checking for a BSD-compatible install... /usr/bin/install -c checking for a thread-safe mkdir -p... /bin/mkdir -p checking for rm... /bin/rm checking for a sed that does not truncate output... /bin/sed checking for ld used by gcc... /usr/bin/ld checking if the linker (/usr/bin/ld) is GNU ld... yes checking for /usr/bin/ld option to reload object files... -r checking for BSD-compatible nm... /usr/bin/nm -B checking how to recognize dependent libraries... pass_all checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking dlfcn.h usability... yes checking dlfcn.h presence... yes checking for dlfcn.h... yes checking how to run the C++ preprocessor... g++ -E checking for g77... g77 checking whether we are using the GNU Fortran 77 compiler... yes checking whether g77 accepts -g... yes checking the maximum length of command line arguments... 98304 checking command to parse /usr/bin/nm -B output from gcc object... ok checking for objdir... .libs checking for ar... ar checking for ranlib... ranlib checking for strip... strip checking if gcc supports -fno-rtti -fno-exceptions... no checking for gcc option to produce PIC... -fPIC checking if gcc PIC flag -fPIC works... yes checking if gcc static flag -static works... yes checking if gcc supports -c -o file.o... yes checking whether the gcc linker (/usr/bin/ld) supports shared libraries... yes checking whether -lc should be explicitly linked in... no checking dynamic linker characteristics... GNU/Linux ld.so checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... no configure: creating libtool appending configuration tag "CXX" to libtool checking for ld used by g++... /usr/bin/ld checking if the linker (/usr/bin/ld) is GNU ld... yes checking whether the g++ linker (/usr/bin/ld) supports shared libraries... yes checking for g++ option to produce PIC... -fPIC checking if g++ PIC flag -fPIC works... yes checking if g++ static flag -static works... yes checking if g++ supports -c -o file.o... yes checking whether the g++ linker (/usr/bin/ld) supports shared libraries... yes checking dynamic linker characteristics... GNU/Linux ld.so (cached) (cached) checking how to hardcode library paths into programs... immediate appending configuration tag "F77" to libtool checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... no checking for g77 option to produce PIC... -fPIC checking if g77 PIC flag -fPIC works... yes checking if g77 static flag -static works... yes checking if g77 supports -c -o file.o... yes checking whether the g77 linker (/usr/bin/ld) supports shared libraries... yes checking dynamic linker characteristics... GNU/Lin
Re: [Discuss-gnuradio] USRP2 Simultaneous Tx and Rx Transmit Errors
> Matt made some changes in the USRP2 FPGA and firmware code in > changeset 10762 that we believe fixes this problem. > > Can you please download and try the lastest FPGA image and firmware > from http://gnuradio.org/releases/usrp2-bin/trunk and let us know if > this fixes it for you. > > FYI, at high data rates, full-duplex, the firmware becomes a > bottleneck and will limit the maximum reliable throughput > achievable. Fixing that will most like require moving at least some > of the state machine that's currently implemented by firmware into the > FPGA fabric. > > Eric > I tested the new FPGA and firmware changes and everything seems to work well down to a decimation and interpolation of 28. Thanks for the fix! Kyle ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] IP3 of Flex 900 boards
Thank you Matt. The IP3 measurement that I did was with 0 gain. I was thinking that the value was very optimistic. Was hoping someone had a value for it. Regards. On Wed, Apr 8, 2009 at 3:25 AM, Matt Ettus wrote: > sHabzbd wrote: > >> Hi Everyone: >> >> Is there any information on the IP3 of Flex 900 boards. I was not lucky to >> find any specification documents on the boards. >> I tried doing some experiments to find out the IP3 and my results show >> 37.5dBm, that is a good figure. I am not too sure whether it really is so >> high. >> If anyone could please help me with any information that you may have >> regarding the IP3 of Flex 900 boards, to that matter any other board will >> also give me a decent idea about these boards. >> > > The IP3 is a function of the gain setting you choose. But in any case, > your measurement of 37.5 dBm sounds very optimistic for any radio. > > Matt > -- Shabbir Ahmed PhD. Student Centre for Telecommunications and Microelectronics Victoria University Email: shabbir.ah...@live.vu.edu.au ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] USRP2 Simultaneous Tx and Rx Transmit Errors
On Wed, Mar 25, 2009 at 01:13:32PM -0700, Johnathan Corgan wrote: > 2009/3/25 Kyle Pearson : > > > When I try to simultaneously transmit and receive a sine wave source > > on one USRP2 using GRC, there appear to be phase discontinuities in > > the transmitted waveform(as if packets from the computer to the usrp2 > > for transmit are possibly being lost or garbled). This only occurs > > when transmitting and receiving at the same time, and when I connected > > the tx signal to a spectrum analyzer it showed random spurs in > > addition to the expected peak from the signal. When only transmitting > > the output on a spectrum analyzer confirms that the transmits properly > > and when receiving a signal from a signal generator there are no > > errors. This occurred even when the decimation and interpolation rate > > was set to 512 and I tried a different ethernet cable but the problem > > still persists. Kyle, Matt made some changes in the USRP2 FPGA and firmware code in changeset 10762 that we believe fixes this problem. Can you please download and try the lastest FPGA image and firmware from http://gnuradio.org/releases/usrp2-bin/trunk and let us know if this fixes it for you. FYI, at high data rates, full-duplex, the firmware becomes a bottleneck and will limit the maximum reliable throughput achievable. Fixing that will most like require moving at least some of the state machine that's currently implemented by firmware into the FPGA fabric. Eric ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] QPSK phase noise
Thanks for your email Eric,
no, there is no underrun or overrun, the CPU usage is really low (even with
the loggin activated), i am running it on a i7 processor.
you usually get a much sharper constellation, don't u?
On Tue, Apr 7, 2009 at 8:34 PM, Eric Blossom wrote:
> On Tue, Apr 07, 2009 at 11:07:54AM -0700, Paco Garcia wrote:
> >
> > Dear All,
> >
> > I am trying to demod a qpsk from another USRP but with the setup below I
> get
> > a really noisy constellation:
> >
> > http://img231.imageshack.us/img231/2465/screenshotysh.png
> >
> > The 2 USRPs are connected via a SMA cable with 40 db attenuators and DC
> > blocker.
> > I have also played with the costas alpha, samples per symbol, gain mu,
> > frequency fine tunning and this is the best result I can get.
> >
> > ./benchmark_tx.py -m dqpsk -f 1.25G -m dqpsk --tx-amplitude=1 -r 1M
> -M
> > --excess-bw=0.35
> > ./benchmark_rx.py -r 1M -m dqpsk --log --costas-alpha=0.05 -S 4 --verbose
> -r
> > 1M --gain-mu=0.01 --excess-bw=0.35 -f 1.25G
> >
> > Thanks for your help.
>
> Are you getting overruns ("uOuO") on the rx side?
> If so, try running at a lower data rate, say 500k.
>
> Eric
>
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Re: [Discuss-gnuradio] QPSK phase noise
On Tue, Apr 07, 2009 at 11:07:54AM -0700, Paco Garcia wrote:
>
> Dear All,
>
> I am trying to demod a qpsk from another USRP but with the setup below I get
> a really noisy constellation:
>
> http://img231.imageshack.us/img231/2465/screenshotysh.png
>
> The 2 USRPs are connected via a SMA cable with 40 db attenuators and DC
> blocker.
> I have also played with the costas alpha, samples per symbol, gain mu,
> frequency fine tunning and this is the best result I can get.
>
> ./benchmark_tx.py -m dqpsk -f 1.25G -m dqpsk --tx-amplitude=1 -r 1M -M
> --excess-bw=0.35
> ./benchmark_rx.py -r 1M -m dqpsk --log --costas-alpha=0.05 -S 4 --verbose -r
> 1M --gain-mu=0.01 --excess-bw=0.35 -f 1.25G
>
> Thanks for your help.
Are you getting overruns ("uOuO") on the rx side?
If so, try running at a lower data rate, say 500k.
Eric
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Re: [Discuss-gnuradio] QPSK phase noise
Thanks for your email Eric,
no, there is no underrun or overrun neither at the Tx or Rx side, the CPU
usage is really low (even with the loggin activated), i am running it on a
intel i7 processor.
you usually get a much sharper constellation, don't u?
On Tue, Apr 07, 2009 at 11:07:54AM -0700:
Are you getting overruns ("uOuO") on the rx side?
If so, try running at a lower data rate, say 500k.
Eric
--
View this message in context:
http://www.nabble.com/QPSK-phase-noise-tp22934944p22935373.html
Sent from the GnuRadio mailing list archive at Nabble.com.
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Re: [Discuss-gnuradio] QPSK phase noise
On Tue, Apr 7, 2009 at 11:49 AM, Paco Garcia wrote: > you usually get a much sharper constellation, don't u? That depends on your overall SNR. I'd suggest trying lowering your transmit power, as the amplitude you are using is driving the RFX into non-linearity, and with the raised cosine filter you are using, the modulation is no longer constant envelope, so you are generating unnecessary distortion. The RFX boards typically remain linear up to an output amplitude of about 2000. Similarly, on receive, it looks like you are using the default mid-point gain of the RFX, which likely too high for a path loss of only 40dB. I'd suggest experimenting with lower receive gains to see if things improve. Johnathan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
RE: [Discuss-gnuradio] QPSK phase noise
Dear All, I'm looking for a processing block to calculate the medium value of a signal. In fact, I should implement the expression attached. Is there anybody here who knows the block I'm looking for? Thanks for your help. -- Alysson Vasconcelos Gomes de Menezes Graduando em Engenharia Elétrica Universidade Federal de Campina Grande - www.ufcg.edu.br Centro de Engenharia Elétrica e Informática - www.ceei.ufcg.edu.br _ Descubra seu lado desconhecido com o novo Windows Live! http://www.windowslive.com.br<>___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] QPSK phase noise
Dear All, I am trying to demod a qpsk from another USRP but with the setup below I get a really noisy constellation: http://img231.imageshack.us/img231/2465/screenshotysh.png The 2 USRPs are connected via a SMA cable with 40 db attenuators and DC blocker. I have also played with the costas alpha, samples per symbol, gain mu, frequency fine tunning and this is the best result I can get. ./benchmark_tx.py -m dqpsk -f 1.25G -m dqpsk --tx-amplitude=1 -r 1M -M --excess-bw=0.35 ./benchmark_rx.py -r 1M -m dqpsk --log --costas-alpha=0.05 -S 4 --verbose -r 1M --gain-mu=0.01 --excess-bw=0.35 -f 1.25G Thanks for your help. -- View this message in context: http://www.nabble.com/QPSK-phase-noise-tp22934944p22934944.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] [benchmark_ofdm]
Hi, I'm using benchmark_ofdm tx and rx in 2.4 GHz. I'm trying to transmit a fixed size of payload everytime (1328 Bytes). My problem is I don't know what values I must put in the parameters: fft-length, occupied-tones, cp-length. I know that fft-length is the total number of subcarriers, cp the cyclic prefix, occupied-tones number of subcarriers used for data. I have been running modifications of these benchmarks, and the best performance I get is when the values of these parameters are: fft-length 512, cp 128, occupied tones 300. In this case, the 80 % of paquetes I receive are right. How can I calculate the apropiate values ? Must I used the parameter "-s" for fixed the packet size to the one I want, 1328? what happen with the "-i" and "-d" in the transmitter and the receiver? Thank you -- View this message in context: http://www.nabble.com/-benchmark_ofdm--tp22934256p22934256.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] Collision Detection
Hi, I am doing my UG project on tactical packet radio. I am almost done with physical layer in gnuradio and now gonna strart work on MAC. I am willing to impliment CSMA (p-persistant) but before diving into it i want to know that if it is possible to do collision detection in gnuradio and how? -- Sajjad Sarwar ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] IP3 of Flex 900 boards
sHabzbd wrote: Hi Everyone: Is there any information on the IP3 of Flex 900 boards. I was not lucky to find any specification documents on the boards. I tried doing some experiments to find out the IP3 and my results show 37.5dBm, that is a good figure. I am not too sure whether it really is so high. If anyone could please help me with any information that you may have regarding the IP3 of Flex 900 boards, to that matter any other board will also give me a decent idea about these boards. The IP3 is a function of the gain setting you choose. But in any case, your measurement of 37.5 dBm sounds very optimistic for any radio. Matt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] BBN 802.11b questions
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Colby Boyer wrote: > Also, does anyone know if the BBN code on the USRP could communicate > with hardware 80211b (ASIC) equipment? I've heard that there are issues > with ack latency. If there is a problem, did the BBN people bother to > implement the acks in their code? > As I recall, the transmit functionality of the original BBN code was not standards compliant: due to the limited bandwidth of the USRP1 it did not actually do DSSS (or CCK, etc.) - it created the frame, and used DBSK (and possibly DQPSK) - but I don't think it did any sort of spreading. Doug - -- Doug Geiger Research Assistant Communications and Signal Processing Lab Oklahoma State University http://cspl.okstate.edu douglas.gei...@okstate.edu doug.gei...@ieee.org -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (Cygwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD4DBQFJ24i+gfOzzR5bXIgRAlujAJYoTn0j6X04U9RK70O/4riBjIEyAKCTSTyC s1nrGmITgBy6yJ12pj4evw== =B03s -END PGP SIGNATURE- ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Help initial problems with the USRP2
On Tue, Apr 07, 2009 at 03:41:18PM +0200, Ane Andersen wrote: > Hi > Hope somebody will help me get a little futher with my USRP2. I have no > previous experience with USPRS, ubuntu or python. > I am running Ubuntu 8.10 and latest version of gnuradio. > > I tried find_usprs and got a response MACaddress and HW_rev 0x0301 from the > box. > > Then I tried running usrp2_fft.py and usrp2_rx_cfile.py with RFX1200 mounted > and also without any card mounted. > With the RFX1200 mounted I in both cases get the following response > > Usage: "filname" [Options] > > Options: > -h -help > -m > etc. > Trying different options I still get the same response > If I remove the daugtherboard. > The system responses with Runtimerror: Unable to retrive daughterboard info > > Is there anybody out there that can help me? Download and install the latest FPGA and firmware images onto the SD Card. http://gnuradio.org/releases/usrp2-bin/trunk Eric ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] [Douglas Geiger BBN 802.11b] Porting code on USRP2 problems
Thank you for your help, the error disappeared Ben Yahmed Johnathan Corgan wrote: The issue is with the output signature being declared in the last part of the above line. It is trying to create a hierarchical block with a variable number of output ports. This functionality is not yet supported. In the past, we silently ignored this, and if the block didn't actually try to use the feature, it would work okay. To be more robust, we recently made this a hard error, which is why the above error message started happening. Looking at the code, it appears that all you need to do is change the line to have an output signature of 1, 1 instead of 1, 2. Johnathan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] [Douglas Geiger BBN 802.11b] Porting code on USRP2 problems
On Tue, Apr 7, 2009 at 5:02 AM, Ben Yahmed wrote: > File "/root/usrp2_version/gr-bbn/src/examples/bbn_80211b.py", line 95, in > __init__ > gr.hier_block2.__init__(self, "bbn_80211b", gr.io_signature(1, 1, > gr.sizeof_char), gr.io_signature(1, 2, gr.sizeof_gr_complex)) > RuntimeError: Hierarchical blocks do not yet support arbitrary or > variable numbers of inputs or outputs (bbn_80211b) The issue is with the output signature being declared in the last part of the above line. It is trying to create a hierarchical block with a variable number of output ports. This functionality is not yet supported. In the past, we silently ignored this, and if the block didn't actually try to use the feature, it would work okay. To be more robust, we recently made this a hard error, which is why the above error message started happening. Looking at the code, it appears that all you need to do is change the line to have an output signature of 1, 1 instead of 1, 2. Johnathan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] I need help from you.
> I installed GNU Radio , now i want to install GSSm package. > > Please anyone can help me out where to get it and how to use that package. Did you read the instructions? http://thre.at/gsm/ It's the first hit on google for "gssm gnuradio": http://www.google.com/search?hl=en&q=gssm+gnuradio&btnI=I'm+feeling+lucky&aq=0&oq=gssm+gnu Jason ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Help initial problems with the USRP2
Hi Hope somebody will help me get a little futher with my USRP2. I have no previous experience with USPRS, ubuntu or python. I am running Ubuntu 8.10 and latest version of gnuradio. I tried find_usprs and got a response MACaddress and HW_rev 0x0301 from the box. Then I tried running usrp2_fft.py and usrp2_rx_cfile.py with RFX1200 mounted and also without any card mounted. With the RFX1200 mounted I in both cases get the following response Usage: "filname" [Options] Options: -h -help -m etc. Trying different options I still get the same response If I remove the daugtherboard. The system responses with Runtimerror: Unable to retrive daughterboard info Is there anybody out there that can help me? Br Ane ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: help for peak detector
Markus Feldmann gmx.de> writes: > > Therefore i have some questions: > To 2.) What allowed values for ? > And what does this mean ? Which unit ? > What is Alpha, and which are allowed values ? > If the peak detector gets a peak, what does it spit > out ? > Which are the allowed values for , > is this in db or a linear factor ? > I studied some of the theory to the EWMA(exponentially weighted moving average), so i think the can be easily deactivated by setting this to 0. As i understand, the tries to wait until inputs from the future are done and take this into the computing of the average ? Because the description of the Peak Detector talks about i think the is a factor meaningfully greater than <1.0> ? The alpha seems to weight the input values, which are be computed for the average, but i think it also results in a average computing of a longer time ? The alpha should be meaningfully 0 < alpha <= 1.0 . Is this correct ? A other Problem is that the Peak Detektor freezes the graphical elements, but i don't get any overrun/underrun. I have got a decimation of 256 and a sample_rate of 250k. Are there known Problems with the Peak Detector ? Regards Markus ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] [Douglas Geiger BBN 802.11b] Porting code on USRP2 problems
Hi all, I'm very interested in the code you are discussing and as a first step I installed gnuradio and the svn code taken from https://www.cgran.org/browser/projects/bbn_80211/branches/usrp2_version on a fedora core 10 and tried to test the bbn_80211b_test.py, but I encountred this problem: # ./bbn_80211b_test.py >>> gr_fir_ccf: using SSE Traceback (most recent call last): File "./bbn_80211b_test.py", line 120, in main() File "./bbn_80211b_test.py", line 101, in main tb = my_block(rx_callback, options.spb, options.alpha, options.snr) File "./bbn_80211b_test.py", line 53, in __init__ self.packet_transmitter = bbn_80211b_mod_pkts(spb=spb, alpha=alpha, gain=1) File "/root/usrp2_version/gr-bbn/src/examples/bbn_80211b_pkt.py", line 67, in __init__ self.xpsk_mod = bbn_80211b.bbn_80211b_mod(*args, **kwargs) File "/root/usrp2_version/gr-bbn/src/examples/bbn_80211b.py", line 95, in __init__ gr.hier_block2.__init__(self, "bbn_80211b", gr.io_signature(1, 1, gr.sizeof_char), gr.io_signature(1, 2, gr.sizeof_gr_complex)) File "/usr/local/lib/python2.5/site-packages/gnuradio/gr/hier_block2.py", line 42, in __init__ self._hb = hier_block2_swig(name, input_signature, output_signature) File "/usr/local/lib/python2.5/site-packages/gnuradio/gr/gnuradio_swig_py_runtime.py", line 1009, in hier_block2_swig return _gnuradio_swig_py_runtime.hier_block2_swig(*args, **kwargs) RuntimeError: Hierarchical blocks do not yet support arbitrary or variable numbers of inputs or outputs (bbn_80211b) do you have any idea about the origin of this problem? Thank you in advance. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] I need help from you.
Hi all, I installed GNU Radio , now i want to install GSSm package. Please anyone can help me out where to get it and how to use that package. Thanks in advance. Regards, Basha. _ So many new options, so little time. Windows Live Messenger. http://www.microsoft.com/india/windows/windowslive/messenger.aspx___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
