Re: Gnuradio 3.8 on embedded [ARM] systems

2021-12-01 Thread jean-michel . friedt
>> https://github.com/oscimp/PlutoSDR/blob/master/doc/gnuradio_on_RPi.pdf > > That link didn't work for me; > https://raw.githubusercontent.com/oscimp/PlutoSDR/master/doc/gnuradio_on_RPi_English.pdf > does. Indeed apologies for changing the tree structure: we decided to split our local Buildroot

Re: [Discuss-gnuradio] "gnuradio challenges" (for learning GNU Radio)

2019-02-14 Thread Jean-Michel FRIEDT
if there can be any interest, I try to gradually go from basics (using GNU Radio to introduce such topics as decimating, aliasing and the need for low pass filtering) to more applied topics (of course FM radio demodulation, then POCSAG) and BPSK demodulation (Costas loop) and finally

[Discuss-gnuradio] European GNU Radio Days conference: call for contribution & registration deadline

2019-01-23 Thread Jean-Michel FRIEDT
The European GNU Radio Days is a conference organized in Besancon (France) June 17th & 18th (2019) aimed at fostering interaction between users and developers of the GNU Radio digital signal processing framework. The first day of the conference is dedicated to oral and poster presentations as

[Discuss-gnuradio] GRCon2017 program and presentations ?

2018-10-08 Thread Jean-Michel FRIEDT
I had bookmarked www.gnuradio.org/grcon-2017/program/grcon17-presentations for accessing the GNURadio conference 2017 program and I believe slides of the presentations. This page is gone, and I cannot find an alternative: is there a place where these documents might still be found ? Thanks,

Re: [Discuss-gnuradio] gr-fec Viterbi example

2018-08-10 Thread Jean-Michel FRIEDT
I tried building this program on Windows and failed. Since it's missing in viterbi/CmakeLists.txt, I fail to see it's built by default. How did you compile it? Are you sure it wasn't written on a big-endian machine? under GNU/Linux g++ -c encode.cc gcc -c viterbi.c gcc -c tab.c gcc -c metrics.c

Re: [Discuss-gnuradio] gr-fec Viterbi example

2018-08-10 Thread Jean-Michel FRIEDT
#define POLYA 0x6d #define POLYB 0x4f If I modify viterbi.c in gr-fec/viterbi (swapping the polynomial coefficients) #define POLYB 0x6d #define POLYA 0x4f then $ xxd word.bin : 1acf fc1d and $ cat word.bin | ./encode > t then t is

[Discuss-gnuradio] gr-fec Viterbi example

2018-08-10 Thread Jean-Michel FRIEDT
I am currently investigating LRPT (as used by METEOR-M2) and am stuck with the Viterbi decoder. While trying to use https://github.com/gnuradio/gnuradio/blob/master/gr-fec/lib/viterbi/decode.cc which implements /* The two generator polynomials for the NASA Standard K=7 code. * Since these

Re: [Discuss-gnuradio] sound card output issue

2018-07-19 Thread Jean-Michel FRIEDT
floor? [Sent from mobile device] On Thu, Jul 19, 2018, 4:49 AM Jean-Michel FRIEDT < jean-michel.fri...@femto-st.fr> wrote: I have a funny problem with the output of a sound card fed from a signal source. The hardware setup is a Scarlett 18i8 sound card sampled at 192 kHz (for VLF

[Discuss-gnuradio] sound card output issue

2018-07-19 Thread Jean-Michel FRIEDT
I have a funny problem with the output of a sound card fed from a signal source. The hardware setup is a Scarlett 18i8 sound card sampled at 192 kHz (for VLF signal analysis) with the signal generated from the front output number 1 (channel number 3 in the GNURadio audio sink). The sound card

Re: [Discuss-gnuradio] Changing delay block value over time

2018-05-24 Thread Jean-Michel FRIEDT
possibly an ugly hack, but I use the Function Probe plugged to a Signal Source to tune the variable delay between two signals. An example is at http://jmfriedt.sequanux.org/xcorrdemo.grc. JM I'd recommend that, yes :) But then again, the delay block you're referring to only allows for full

Re: [Discuss-gnuradio] VCO

2018-05-17 Thread Jean-Michel FRIEDT
I would like to ask about the VCO in GRC. What's the function of the sensitivity? If I connect a signal source (Saw Tooth) into VCO, and I want a bandwidth of 2MHz. I only can achieve it by setting the Sentivity = 2e6 *(2*3.1416) . Can anyone explain the theory behind this? may the

Re: [Discuss-gnuradio] VCO

2018-05-17 Thread Jean-Michel FRIEDT
I would like to ask about the VCO in GRC. What's the function of the sensitivity? If I connect a signal source (Saw Tooth) into VCO, and I want a bandwidth of 2MHz. I only can achieve it by setting the Sentivity = 2e6 *(2*3.1416) . Can anyone explain the theory behind this? may the

[Discuss-gnuradio] reminder: French GNURadio days -- deadline approaching

2018-05-17 Thread Jean-Michel FRIEDT
A quick reminder, for those interested to meet to discuss the latest developments related to GNURadio in France and Europe, that the deadline for submission and registration for the French GNURadio days is approaching (May 20). The web site with the program, template and registration is at

Re: [Discuss-gnuradio] Fwd: RTL-SDR for GPS/Galileo signal reception

2018-04-19 Thread Jean-Michel FRIEDT
. Any help would be highly appreciated. Thank you Priyanka On Thu, Apr 19, 2018 at 8:14 AM, Jean-Michel FRIEDT < jean-michel.fri...@femto-st.fr> wrote: I am collecting from the RTL-SDR dongle has amplitude in range of 0.04(peak to peak). Can we be sure of having GPS signal it and is su

Re: [Discuss-gnuradio] Fwd: RTL-SDR for GPS/Galileo signal reception

2018-04-19 Thread Jean-Michel FRIEDT
I am collecting from the RTL-SDR dongle has amplitude in range of 0.04(peak to peak). Can we be sure of having GPS signal it and is such low strength of signal okay for GPS acquisition or not? that's the beauty of spectrum spreading and pulse compression: despite the signal being below thermal

Re: [Discuss-gnuradio] Fwd: RTL-SDR for GPS/Galileo signal reception

2018-04-18 Thread Jean-Michel FRIEDT
If you want to make sure that your collected data include GPS signals, get rid of the BPSK modulation by squaring the complex signal, see http://jmfriedt.free.fr/trans_num_l3_1_eng.pdf slides 37-38. I tried to do my best to describe the demodulation process in

[Discuss-gnuradio] Announcement: French GNU Radio days, July 2-3 2018

2018-04-12 Thread Jean-Michel FRIEDT
Call for contribution: First French GNU Radio days -- It is our pleasure to announce the first meeting centered around the GNU Radio framework held in France (Lyon). This workshop targets French and European GNU Radio users and developers.

[Discuss-gnuradio] gr-paint and FM capture: review request

2018-04-01 Thread Jean-Michel FRIEDT
I have just completed a text summarizing my latest investigation on painting on the radiofrequency spectrum (i.e. gr-paint) and the impact of the FM capture effect from a nearby interfering signal, including the justification of using AM modulation in aeronautical communications. Since these are

Re: [Discuss-gnuradio] Getting signal from a LEO Satellite? ( Doppler shift handling)

2017-10-26 Thread Jean-Michel FRIEDT
costas will do the job as long as your measurement bandwidth includes twice the expected frequency offset, see http://jmfriedt.free.fr/efts_gps.pdf slide 13. JM I am planning to track a signal from a LEO Satellite which transmits approx. 100 kbps BPSK. I wonder which blocks should I use since

Re: [Discuss-gnuradio] FFT normalization issue: noise aliasing

2017-10-15 Thread Jean-Michel FRIEDT
PS: the fact that reducing by 10 the number of samples in the FFT rises the noise level by 10 dB definitely hints at dB/Hz rather than dB as Y-axis unit. JM This message was sent using IMP, the Internet Messaging Program.

Re: [Discuss-gnuradio] FFT normalization issue: noise aliasing

2017-10-15 Thread Jean-Michel FRIEDT
Shouldn't my aliasing experiment raise the noise floor rather than keep it constant ? By taking only every 10th sample, you also reduce the sample rate by a factor of 10. So you have the same power in 1/10th of the original bandwidth. In other words, noise power per Hz has increased by a factor

[Discuss-gnuradio] FFT normalization issue: noise aliasing

2017-10-15 Thread Jean-Michel FRIEDT
I want to demonstrate how aliasing rises the noise level upon decimation. I have a trivial flow graph with a noise source, whose bandpass I limit to make sure I know its spectral characteristics, and I compare the spectral power with and without decimation. The decimation FIR is 1 so I believe

Re: [Discuss-gnuradio] RDS decoding

2017-04-02 Thread jean-michel . friedt
I have just completed the translation to English of my description of RDS decoding. It is now available at http://jmfriedt.free.fr/lm_rds_eng.pdf Corrections welcome, both on the content (not familiar enough with error correcting codes and bitrate synchronization to be sure I did't make

Re: [Discuss-gnuradio] Request for volunteers: FOSDEM Videos (even if you're not going to FOSDEM!)

2016-12-30 Thread jean-michel . friedt
I will be attending the whole session and will be available any time I am needed to help with checking the video/audio (from last year, I am still not sure I know what to do in case of failure). JM > First of all, thanks Sylvain for volunteering. > > But, it's still only Sylvain and myself, so

[Discuss-gnuradio] FOSDEM videos

2016-02-23 Thread jean-michel . friedt
The videos of the FOSDEM talks are now available at https://video.fosdem.org/2016/aw1125/ Status: OK: 'Building Self-Optimizing Radios using DEAP' OK: 'Embedded SDR' OK: 'News from the OAI Community' OK: 'Prototyping the 5G Air Interface in GNU Radio: An FBMC Primer' OK: 'Radio Machine Learning

Re: [Discuss-gnuradio] gr-osmosdr issues ?

2016-01-11 Thread Jean-Michel FRIEDT
Thanks for the answers. All sampling rates are in the 1.5-2.5 MHz range, namely 11025*128=1.4112 MHz when decoding POCSAG, or 48000*32=1.536 MHz when decoding commercial FM (for these trivial tests). The issue about synchronization only arises when an audio sink is used: sending the data to a

Re: [Discuss-gnuradio] gr-osmosdr issues ?

2016-01-11 Thread Jean-Michel FRIEDT
Thanks for the answers. All sampling rates are in the 1.5-2.5 MHz range, namely 11025*128=1.4112 MHz when decoding POCSAG, or 48000*32=1.536 MHz when decoding commercial FM (for these trivial tests). The issue about synchronization only arises when an audio sink is used: sending the data to a

Re: [Discuss-gnuradio] detecting covert RFID scans

2015-12-28 Thread jean-michel . friedt
I'll discuss a bit of passive RFID at FOSDEM ... I think there are two parts to the question: detecting RFID measurement attempts on the one hand, and decoding the backscattered signal on the other hand. Detecting RFID is, imho, obvious: because the backscattered signal decays as 1/d^6 for an

Re: [Discuss-gnuradio] R820T2/RTL2838U

2015-08-13 Thread Jean-Michel FRIEDT
these are two chips of the same device (RF front end and ADC to USB converter) and yes, they do work well with the osmosdr source of gnuradio. JM Please, does someone know if these two RTL devices (R820T2 and RTL2838U) work fine with Gnuradio? Which is better? Thanks a lot. Cheers, Antony

Re: [Discuss-gnuradio] multiple sources synchronization ?

2015-07-22 Thread jean-michel . friedt
There's nothing in your system that would make both RTL dongles and the soundcard start sampling at the same time, so naturally there's a large time offset between these. You will need to time align these signals first, before you can use the sound card signal to determine in which state

[Discuss-gnuradio] multiple sources synchronization ?

2015-07-22 Thread jean-michel . friedt
Possibly a stupid question, but might help me better understand how the gnuradio scheduler works: my objective is to make a low cost phase-referenced radiofrequency interferometer using two DVB-T dongles. Since I have observed that the PLL inside each dongle induces slow phase drift, I want

Re: [Discuss-gnuradio] Regular FM radio fine, POCSAG horrible

2015-06-02 Thread jean-michel . friedt
If it can be of any help, I use POCSAG to illustrate one of the SDR labs I teach: the flowcharts are pp.4 and 5 of http://jmfriedt.free.fr/tp_sdr.pdf (don't mind the text in French, only look at the pictures) and the associated videos are at http://jmfriedt.free.fr/ (first two ones from the top).

[Discuss-gnuradio] dual receiver setup for interferometry measurements

2015-05-28 Thread jean-michel . friedt
I have a question concerning connecting two DVB-T dongles on the same clock source for interferometric (or passive radar) measurements, as described at http://kaira.sgo.fi/2013/09/16-dual-channel-coherent-digital.html I have assembled the same system with one dongle used as oscillator on a 28.8

Re: [Discuss-gnuradio] dual receiver setup for interferometry measurements

2015-05-28 Thread jean-michel . friedt
Thanks for your reply. Indeed designing phase coherent receivers is my daily job activity (partly), but the fun of hacking DVB-T receivers is to find ways of using these for applications they were never intended for. I have indeed read your posts concerning the difficulties in reproducing

Re: [Discuss-gnuradio] R820T frequency tuning issue

2015-03-28 Thread jean-michel . friedt
As a quick followup to my previous post, I confirm that the R820T is well suited for GPS signal decoding. I was not expecting the huge frequency offset ( 100 kHz at 1.57 GHz) and was not searching far enough from the expected carrier frequency during the acquisition phase. However these results

Re: [Discuss-gnuradio] R820T frequency tuning issue

2015-03-28 Thread jean-michel . friedt
Your results are consistent with what I've heard about the R820T above 1500MHz or so. It starts to become deaf, and then as you move higher, the PLL won't lock at all. I loose 10 dB sensitivity from 1.50 GHz to 1.575 GHz ! At 1.5 GHz the R820T was more sensitive than the E4k, but now

[Discuss-gnuradio] feedback loop for bpsk carrier recovery ?

2014-10-23 Thread jean-michel . friedt
For educational purposes, I am investigating a carrier recovery scheme for BPSK demodulation. I have synthesized a BPSK modulated signal, assembled a hardware carrier recovery scheme which works well (squaring the modulated signal, bandpass filtering and dividing, aka Costas loop) which I now

[Discuss-gnuradio] git access to UHD through http ?

2014-01-05 Thread Jean-Michel FRIEDT
not sure if this issue is relevant to the mailing list: while running the tutorial at https://github.com/balister/oe-gnuradio-manifest which aims at recovering all tools needed to build an image for an embedded architecture, intensive requests to git are performed to fetch all the source codes.

Re: [Discuss-gnuradio] GNURadio on Zync: thanks for the excellent tutorial

2014-01-01 Thread Jean-Michel FRIEDT
to wait :) Philip Vanush On Fri, Dec 27, 2013 at 2:31 AM, Philip Balister phi...@balister.org wrote: On 12/26/2013 02:28 AM, Jean-Michel FRIEDT wrote: I have used the opportunity of the more relaxed days of this Christmas period to try and run the tutorial at http://gnuradio.org/redmine

[Discuss-gnuradio] GNURadio on Zync: thanks for the excellent tutorial

2013-12-25 Thread Jean-Michel FRIEDT
I have used the opportunity of the more relaxed days of this Christmas period to try and run the tutorial at http://gnuradio.org/redmine/projects/gnuradio/wiki/Zynq Wonderful page, works nearly perfectly, thanks a lot. A few minor comments to the author or useful to other readers of the mailing

Re: [Discuss-gnuradio] BESOIN D'AIDE GNURADIO

2013-09-05 Thread Jean-Michel FRIEDT
 je réalise une radio logicielle sous GNU RADIO mais seulement je ne maitrise pas très bien le role des blocs. en fait j'ai besoin d'un amplificateur à gain variable et un démodulateur I/Q. j'arrive pas à retrouver ces bloc sous GNURADIO. si quelqu'un peut me venir en aide je serai très

Re: [Discuss-gnuradio] How to use USRP to detect and collect weak satellite signals

2013-09-04 Thread Jean-Michel FRIEDT
apparently someone else was at OHM ... i had not seen the trick of squaring the GPS signal to get rid of the phase modulation and hence the spread spectrum to only recover the doppler shift elsewhere: looks like a great trick to validate the reception of a GPS signal even below thermal noise

Re: [Discuss-gnuradio] Doppler Radar Processing

2013-07-14 Thread Jean-Michel FRIEDT
in case you are interested in such a related topic http://jmfriedt.free.fr/poster_12906.pdf I have not made an archive of all the related boxes and GRC graphs but this might be an opportunity to do so. JM Has anybody done Doppler Radar Processing in GNU Radio Companion? Currently, I am just