Відео

I'm sure it's possible exporting something from Matlab that the USRP B210 can understand. However I don't have experience with the USRP B210 and how it likes it's baseband signal, but maybe it's a IQ file in a wav format? A real time link between Matlab and USRP B210 would be more difficult but maybe there is someone who has already written some thing to do that. But yeah if it were me I'd start by generating a baseband signal in Matlab, export the signal as a IQ wav file, and then figure out how to transmit the file later after I was pretty confident that the signal was a valid one.

@@jontiolds can we save our signal in bin files from Matlab just like the spoofing video which were created using gnss sdr sim

@@copycarvers I'm not sure what the bin file format you mention is but I guess it's just a raw IQ format, probably 16bits I then 16bits Q, and signed integers. Matlab/Octave you can write that binary sort of stuff to files easily enough. So yes.

Will I need to use simulink for the signal construction or I can construct the signal using Matlab command window. Yes it is the IQ format and can I transmit.it using software defined radios?

@@copycarvers If it were me I'd just make classes and matlab scrips. I wouldn't use simulink mainly as I'm not that familiar with it. Any SDR radio that can transmit and take IQ files will transmit what you want. IQ files are baseband so you have to tell the SDR the frequency you want to transmit on and if it's a raw file format also the sample rate and whether the IQ samples are 16 bit 8 bits, signed, float etc. The SDR transmitter will describe the formats it can deal with you just have to write the binary files in matlab with a format the SDR transmitter wants.

The address seems to work for me it's jontio.zapto.org/hda1/gps_matlab/Legacy%20GPS%20receiver%20in%20Matlab.html all the code is in that webpage. Does that webpage not load for you?

@@jontiolds Thank you for the feedback. However, the access problem has continued still, at least for me. Is there other way to access your site.?

@@ahmetesatsuzer5313 Oh that is odd so it doesn't load? What response does it give (eg 404 etc). My site is self hosted in NZ so maybe your ISP or country doesn't like the IP address? What country are you in? Can you access any pages on my site jontio.zapto.org ? If I can find some proxys from other countries I'll test the connection from there. ps I just tried some proxies from the US and Europe and didn't find any that fail to load. It's odd but you could just use one of the web proxys out there.

Thanks. Glad you like it.

Thanks. I've never looked into spoofing. Spoofing would mean creating a GPS signal so that means you would need to create navigation data then mix that with the prn. If you wanted it so the GPS receiver position would be controllable then I think you would need to do it for most if not all SV visible but I'm not sure. If I was a GNSS receiver engineer to prevent this kind of attack I would use Galileo and Glonass too. Then if one GNSS system didn't match the others I would ditch the suspected spoof signals. If the receiver was multi band then I would compare navigation data from different bands. However multi band receivers are less common. Another way to detect spoofing would be SNR strengths, if all SVs had exactly the same SNR that would be fishy. My guess would be only some GNSS receivers would be easily spoofable. It would be a difficult project to do. If it was me I would start by generating a PRN mixed with some NAV data obtained from the real SV with that PRN and then transmitting it. I would then experiment with times such as TOC TOE HOW etc to make the recording seem to advance in time.

@@jontiolds thank you for reply, yeh that's pretty much how we can detect the spoofing but for that 1st i need to generate spoofing signals to actually make the receiver to show false location. I have already generated the prn, and mixed it with the NAV data but the problem is in transmission. When I transmit it @1575.42MHz ,L1 signal's freq. The receiver is not be able to lock onto those signal (all exp is done in open sky and static environment) also the C/No is too low.

@@Itsmesam99 as I don't know your setup I can only guess as to what maybe happening. Have you experimented with the signal you are trying to send rather than actually transmitting it on air? Are you able to use something like my Matlab code to de-spread and track the signal you want to send? If yes to all those then are you able to transmit an L1 signal in a quiet indoors location and do the same using an SDR receiver? Only after that I would then consider using an off the shelf receiver for tests. Even then I would mainly test everything using an SDR receiver shielded from the outside and use my own code so I could be sure as to what I was going to send was what I would want. I think a lot of the effort would be spent generating the navigation data. With the modernization of GPS you may also have to look into CNAV as well as LNAV navigation if your off the shelf receiver is to lock on to your signal rather than the actual one.

@@jontiolds i found this video demonstration for spoofing gps i am applying the same but the problem is when i transmit the signals the receiver it not locking onto those signals. Video- ua-cam.com/video/3NWn5cQM7q4/v-deo.html

Please Lemme know what the problem is ? If you're able to find out Btw am not using hackrf for transmission am using amitec sdrs and gnu radio for transmission of the generated bin file

Thanks glad you like it

Not without hardware modification. You would have to open the transmitter up and get it to transmit mono, then bypass the low frequency and preemphasis section. It would be interesting to try. My guess is those car-lighter transmitters use a single chip that is pretty integrated so might be impossible. Still I'd be very interested if anyone has done this.

No this is MPX and an analog transmission format.

thanks

JMPX is a stereo encoder, Jpic is a piece of hardware. I assume you're asking if the Jpic can be made into MPX encoder? Jpic only has a mono input and I haven't written an MPX encoder for it mainly because of that. So you would need to add another channel into the Jpic or a higher quality option would use an I2S ADC chip to interface with the Jpic to get the stereo input.

8 chars for the ps is defined in the specs I followed and can't be greater with the protocol I used.

I did yes but you don't have to

windows 7 circa 2014 brand Onda. Really liked this computer.

I'm not sure what Radio Dj is and haven't used it. Did a search and seems to be a windows program. I'm not sure.

I'm not sure how you system is exactly setup. I would think what ever component is doing the stereo to MPX encoding in your system is where JMPX should be placed. A soundcard with a good SNR rating that can do 192kHz and an external card I've found better. Using a Raspberry Pi with one of the 192Khz DACs seems to be a popular option but setting things up seems to be a bit tricky for some.

Q: "hello friend how can I change the title of the song automatically" On Linux it uses Dbus and mpris so most audio players will do that for you. On windows I can't remember how I did it but I think it looked at window titles for various applications such as media monkey, vlc and windows media player to figure out what was playing.

Thanks, I'm glad you like it.

That would take me quite a while to write down how to do it. Things change all the time documenting the process can be a frustrating thing as something that worked last year might fail next year. The basic process if you use MSYS2 to install everything (qtcreater qmake qt5), there might be rtaudio, jack etc to install to. When you get an error it's usually because something it needs is not installed.

thanks

That hardware transmitter used to be a stereo one but I disabled the stereo input so only one channel is being used. I assume that I plugged in both channels as I didn't know what one was the channel that modulated the signal and what one did nothing.

This seems to be a common request. Yes it should be something to be added. I did add 5A group that can be sent this way as someone commissioned me to do it. I'll put it on my to do list but it might be a long long time before I get around to doing it.

That's tricky. On Linux I build from scratch and if an error happens it's usually a missing dependency so I install the missing thing and try again. I keep doing that till it's compiled.

Everything seems to save correctly for me after I shut down the application, have you unchecked "Update RT with music title"?. Maybe it's a problem with flipping between RT A and RT B. Try powering off the receiver then turning it back on again and see what happens. The scrolling speed for RT on a radio is controlled by the radio itself I believe. I don't think think I have any control over that. I'm not sure what you mean by "an option start with window". It starts with a window.

Yes you can. Put your name in the RT line edit and uncheck "update RT with music title". As I recall RT can cope with about 32 char. You can put whatever you like in RT.

thanks bro i will test and reply back :)

I haven't added any facility for dynamic PS strings. I don't know if there is an official way of displaying more than 8 characters. I assume you are wanting to flip between two different PS string. You could add something like that to the code but it could have a strange effect on the receiving radio's display of the PS. A PS string is not necessarily transmitted in sequential order so to the end user looking at his or her radio it could look odd and confusing.

thanks @Jonti Olds i mean my station name is LOVE STATION SO HOW I WILL PUT IT ? LIKE AIROMATE DOES IT

I've not used Airomate so I'm not sure how they do it. When I have some spare time I'll have a look at how they do it and see if it's something that could be implemented into JMPX. I know RT can be more than 8 chars but I was not aware that PS could be. Anyway, I'll have a look.

As long as it can do 96,000 or 192,000 bits per second I can only assume it should

For this video I made a single transister transmitter ( github.com/jontio/JMPX/wiki/One-Transistor-Transmitter-Test-example ). The stability was awful but it worked well enough for the quick test. I wouldn't recoment using this transmitter though.

@@jontiolds it connects to usb port or microphone ?

@@jontiolds sorry that i about transmitter with head jack3.5

What OS are you using? Sometimes you may have a sound card that can do 192kHz but the OS sets the actual sample rate to 96kHz. It could be something else but I think that is likely. If you are using Window I suggest you use spectrumlab and set the sample rate to 192kHz and create a tone around 60kHz and see if the soundcard actually produces it.

Good morning Jon. I'm Eli, I work with electronics. I can not install JMPX on ubuntu. Could you help me? Can you send me the procedure or another way to install it? I tried to compile the file in ubuntu but it appears that the file does not exist. ./jmpxencoder File does not exist But he is not enough. Thank you if you can help.

I can only assume it's a file permission issue in Ubuntu. I also suggest you get the latest version of the software using 'git clone github.com/jontio/JMPX' as I believe I have change the name of the executable in Linux to JMPX

Good evening. I tried but it always appears file or directory not found when I run the ./JMPX command in the terminal

I gave permission to all files

+amri muhtasyim Currently you can change the RDS text either from the options menu or from players such as VLC, Mediamonkey etc. So no, you can't use notepad to change the song title.

thanks