Re: [Discuss-gnuradio] Can not get rx time tags

On 09/03/2013 12:41 AM, Harry Zhang wrote: > Hi, > I'm trying to get rx time tags in narrowband Benchmark_tx/rx with a > modified digital_correlate_access_code.cc. But the > "get_tags_in_range(rx_time_tags,0,this->nitems_read(0)+i,this->nitems_read(0)+i+1,pmt::pmt_string_to_symbol("rx_time"))" >

Re: [Discuss-gnuradio] Porting GR-AIS to GN3.7

He Guys, Thank you for the prompt replies, in special Nick Foster for the reply, I am very thankful for the gr-ais package! :) Currently I am working with the modtool. I didn't know it's existence. A very helpful tool. I might have found a bug. I have version 3.7.2git-0-gd19aa281. When I create

[Discuss-gnuradio] Enabling cpu #1 causes math error on ARM target

I wanted to post this observation to the group to see if I get a hit. I updated Bug #569 today with an additional observation: http://gnuradio.org/redmine/issues/569 Basically, on my ARM target, if I enable cpu core #1 (two cores total), the qa_mpsk_receiver test fails about 1/3rd of the time,

[Discuss-gnuradio] Empty work functions

The implementation of the uhd_control_port block in gnuradio-extras has an empty work function because it doesn't actually process any samples. I believe gnuradio-extras uses the gnuradio advanced scheduler (GRAS), so apparently GRAS doesn't mind blocks that don't have any connections in a flowg

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

http://en.wikipedia.org/wiki/SiRF On Wed, Sep 4, 2013 at 11:14 PM, Sylvain Munaut <246...@gmail.com> wrote: > On Wed, Sep 4, 2013 at 2:54 PM, Vanush Vaswani wrote: > > What is the difference between the receiver tech in something like a CSR > > chip vs USRP? > > CSR chip ? > > > Cheers, > >

Re: [Discuss-gnuradio] 3.6.4.2 test fail

I deleted everything concerning my module and installed it again, at it works now. I hate things like that :). Thank you all guys again. P.S. After making 3.6.5.1 teset shown error in udp source aas far as i remember, but then i run ctest -V and there was no error. Best, Nemanja On Wed, Sep 4,

Re: [Discuss-gnuradio] Porting GR-AIS to GN3.7

Side note, is there a data file containing AIS samples for testing anywhere? Philip On 09/04/2013 10:57 AM, Marcus Müller wrote: > Never, it's obsolete; use gr_modtool to generate a 3.7 module, and refer > to the GR wiki for instructions. > > On 04.09.2013 16:53, Driesprong, Fokko wrote: >> Hi M

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

On 09/04/2013 10:56 AM, Marcus Müller wrote: This is like a hard comparison; you can't really compare the two. Howver, both have an ADC. GPS receivers usually have correlator banks to detect the signal, yielding a large processing gain by effectively using half eternity of energy. Well, presu

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

On Wed, Sep 4, 2013 at 2:54 PM, Vanush Vaswani wrote: > What is the difference between the receiver tech in something like a CSR > chip vs USRP? CSR chip ? Cheers, Sylvain ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.

Re: [Discuss-gnuradio] set_command_time ack timeout issue

Ah ok, it is a misunderstanding of mine of how the set_command_time() works then. I was under the impression that the command will still return immediately but instead, any command given after the set_command_time will then hang until the ACK is passed back after the command executes. Will hav

[Discuss-gnuradio] Radar application using UHD HELP

Hi there, I'm really new to *USRP* and *GNURADIO* world, so please you got to be patient. I have a few questions about *UHD*. I've successfully installed GnuRadio and UHD on Ubuntu 13.04 (wich i'm new too). I want to give the USRP a *radar application at 30-55 MHz* and found out that there's an old

Re: [Discuss-gnuradio] Porting GR-AIS to GN3.7

Hi Martin Braun, Thanks for the information. I was aware of that. When can gr-howto-write-a-block for version 3.7 be expected? ​Kind regards, ing. Fokko Driesprong 2013/9/4 Martin Braun (CEL) > FYI: Gruel was removed in 3.7. > > See also: > http://gnuradio.org/redmine/projects/gnuradio/wiki/

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

The majority of thermal noise enterimg the receiver is from the antenna and the path to the LNA. Freeze the antenna and this path, then you may be able to see GPS. Lookup the formula for MDS and it will give you an idea of the temperature you need. Then select a coolant. Thermal noise is ban

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

This is like a hard comparison; you can't really compare the two. Howver, both have an ADC. GPS receivers usually have correlator banks to detect the signal, yielding a large processing gain by effectively using half eternity of energy. On 04.09.2013 16:38, Vanush Vaswani wrote: http://en.wik

Re: [Discuss-gnuradio] 3.6.4.2 test fail

On Wed, Sep 4, 2013 at 4:45 AM, Nemanja Savic wrote: > After installing 3.6.5.1 there is a problem while when running flowgraph. > Flowgraph won't start, and the error is following: > > Using Volk machine: avx_64_mmx > -- Loading firmware image: /usr/local/share/uhd/images/usrp1_fw.ihx... done > -

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

Ruoyu, First off, Singapore is a very noisy place (From a radio perspective), so you are going to have to pair any external low noise amplifiers with appropriate filters for your signals of interest. It is vital that none of the components in the radio signal chain receivers too much power which

Re: [Discuss-gnuradio] Porting GR-AIS to GN3.7

I've been following the discussion and I'm grateful for the porting work to 3.7 as I haven't had time to do it myself. That said, I'm happy to help with gr-ais-specific questions. Here's a sample file recorded a couple of years ago in SF Bay. It was recorded with a USRP1 + WBX at 256ksps. http://

Re: [Discuss-gnuradio] set_command_time ack timeout issue

On 09/04/2013 11:19 AM, Steve Zygmunt wrote: Ah ok, it is a misunderstanding of mine of how the set_command_time() works then. I was under the impression that the command will still return immediately but instead, any command given after the set_command_time will then hang until the ACK is pa

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

>> On Wed, Sep 4, 2013 at 2:54 PM, Vanush Vaswani wrote: >> > What is the difference between the receiver tech in something like a CSR >> > chip vs USRP? Just because you can't see the signal of a FFT doesn't mean you can't demodulate it ... Cheers, Sylvain ___

Re: [Discuss-gnuradio] Porting GR-AIS to GN3.7

Never, it's obsolete; use gr_modtool to generate a 3.7 module, and refer to the GR wiki for instructions. On 04.09.2013 16:53, Driesprong, Fokko wrote: Hi Martin Braun, Thanks for the information. I was aware of that. When can gr-howto-write-a-block for version 3.7 be expected? Kind regards

Re: [Discuss-gnuradio] Could not open large files (KILL)

On Wed, Sep 4, 2013 at 8:35 AM, sunday iliya wrote: > Dear All, > I'm using USRP to capture data at certain interval of time and save the > data in a file. I used the level() method of gr.probe_signal_vc and a vector > length 1024 (samplelength). if the program is run for a short time it works >

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

Hi, > apparently someone else was at OHM ... Yes :) > 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 b

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

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 level

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

What is the difference between the receiver tech in something like a CSR chip vs USRP? On Wed, Sep 4, 2013 at 9:25 PM, Ralph A. Schmid, dk5ras wrote: > > I've actually seen it without de-spreading during a presentation > recently. Of > > course it had been received with a 25 m dish or so :) > >

Re: [Discuss-gnuradio] make test error

Hi Matt - If GNU Radio builds and runs as expected, then there is a very good chance that the issue with VOLK has already been reported and it's more a matter of folks finding time to fix the issue than anything else. If you still wonder, I have already provided the command line to execute to p

[Discuss-gnuradio] Could not open large files (KILL)

Dear All,  I'm using USRP to capture data at certain interval of time and save the data in a file. I used the level() method of gr.probe_signal_vc and a vector length 1024 (samplelength). if the program is run for a short time it works fine and and the files can be opened but if I run the progra

[Discuss-gnuradio] How good can USRPs with internal GPSDOs being synchronized?

Hi all, I am trying to synchronise two USRP N210 with the goal of receiving time-aligned samples. I've modified the rx_samples_to_file.cpp code according to this page: http://files.ettus.com/uhd_docs/manual/html/sync.html It seems that the signals at the USRPs have between +0.2 and -0.2 us time d

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

> I've actually seen it without de-spreading during a presentation recently. Of > course it had been received with a 25 m dish or so :) Yep, brute forced it should be possible :-) Not really the same like with UMTS or LTE... Ralph. ___ Discuss-gnurad

Re: [Discuss-gnuradio] insufficient connected output ports

Thank you Marcus, this works. On Wed, Sep 4, 2013 at 1:03 PM, Marcus Müller wrote: > Hi Nemanja! > None is an object of type NoneType; thus, the output signature list has > length 1; it should have length 0. > Use out_sig=[] instead. > > Greetings, > Marcus > > > On 09/04/2013 12:48 PM, Nemanj

Re: [Discuss-gnuradio] insufficient connected output ports

This is a bit frustrating situation, and I don't know how to solve the problem. I tried to figure out what's going on, and wanted to call function input_signature() from python i norder to see what is

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

Hi, > I would rate GPS as invisible, with normal receiver technology. They are > using a low bitrate, spreaded over a very large frequency range. The only > way to "see" something should be correlating and decoding the stuff. I've actually seen it without de-spreading during a presentation recent

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

> Yeah, seeing GPS is not easy, signals are well below the noise floor AFAIK. I would rate GPS as invisible, with normal receiver technology. They are using a low bitrate, spreaded over a very large frequency range. The only way to "see" something should be correlating and decoding the stuff. Ra

Re: [Discuss-gnuradio] Porting GR-AIS to GN3.7

Hi Marcus, Thanks for the response and thoughts. I am running Ubuntu 12.04 on the beaglebone. I don't use any GUI, and I start the gr-ais script from the commandline. With the cortex A8 and neon co-processor the beaglebone is suprisingly powerfull. Currently I am developing on a Ubuntu 13.10 des

Re: [Discuss-gnuradio] Porting GR-AIS to GN3.7

Gruel really IS a part of GNU Radio. You never need gruel / gruel-dev on a system to compile GNU Radio, since the GR source tree _contains_ gruel. Since it is integral to GR, a gruel from a different version of GNU Radio (which is most probably the case when you install it via your package manag

Re: [Discuss-gnuradio] Porting GR-AIS to GN3.7

FYI: Gruel was removed in 3.7. See also: http://gnuradio.org/redmine/projects/gnuradio/wiki/Move_3-6_to_3-7 MB On Wed, Sep 04, 2013 at 11:55:59AM +0200, Marcus Müller wrote: > Gruel really IS a part of GNU Radio. You never need gruel / gruel-dev on a > system to compile GNU Radio, since the GR s

Re: [Discuss-gnuradio] set_command_time ack timeout issue

Hi Steve, Worth it to submit an additional bug noting the fifo timeout for longer set_command_time()? I think that it > is merely an additional symptom of the issue you found. No, actually I think your timeout after set_command_time is not /really/ a bug, actually. The gr-uhd usrp_source u

Re: [Discuss-gnuradio] 3.6.4.2 test fail

After installing 3.6.5.1 there is a problem while when running flowgraph. Flowgraph won't start, and the error is following: Using Volk machine: avx_64_mmx -- Loading firmware image: /usr/local/share/uhd/images/usrp1_fw.ihx... done -- Opening a USRP1 device... -- Loading FPGA image: /usr/local/sha

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

Hi, > 1. USRP N210, DBSRX2 800-2400MHz > 2. Minicircuit cable amplifier, provides 37 dB gain at 15V/0.68A supply > input. To ensure signal is enough enhanced, I used two of them in recent > experiments. > 3. Horn antenna with frequency range from 0.8 - 18 GHz. beamwidth 60 degree. You probably wa

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

Hi, All I am working on a project which requires to receive signals from LEO satellites like orbcomm and iridium. I tried to use USRP N210 to collect the data, but I found the signal may be too weak to be observed. Stuffs I used: 1. USRP N210, DBSRX2 800-2400MHz 2. *Minicircuit* cable amplifier,