Tagged: gnu radio

Tech Minds: Making your own SDR Software With GNU Radio Companion

In his latest video out on YouTube, Matt from the Tech Minds channel gives us an overview of GNU Radio, and shows a few examples of how it can be used to receive, transmit and decode digital data.

GNU Radio is a popular open source DSP framework for software defined radios. With it you can graphically implement any sort of digital signal processing chain that you like, which can be used for decoding/encoding and demodulating/modulating signals.

GNU Radio can be extremely complex and powerful, but in the video Matt shows some simple starter example flowgraphs like an LSB demodulator, and a simple wav file source transmitter for the HackRF. 

How To Make Your Own SDR Software With GNU Radio Companion

Reminder: GNU Radio Conference 2023 Starts September 5 MST

This is a reminder that GNU Radio Conference 2023 (GRCon23) will be starting tomorrow on September 5 in Mountain Standard Time (MST) and will run until September 9.

GNU Radio conference talks are generally about cutting edge radio research topics and applications that involve the use of GNU Radio, a popular DSP framework for SDRs. If you are interested, previous years talks can be found on the GNU Radio YouTube channel.

The talks at GRCon23 will be livestreamed on YouTube for free, and we have pasted the links to each days live stream link below. We recommend activating YouTube notifications on each video so you won't miss the start.

There is also a virtual conference chat available. Links to the various rooms are available on the participants guide website.

GNU Radio Conference 2023 to be held September 5 – 9: Call for Participation and Registration is Open

Thank you to Marcus Müller for letting us know that a call for participation and registration for GRCon'23 (GNU Radio Conference 2023) is currently open. GNU Radio conference talks are generally about cutting edge radio research topics and applications that involve the use of GNU Radio, a popular DSP framework for SDRs. If you are interested, previous years talks can be found on the GNU Radio YouTube channel.

The deadline for participation to present is still open, having been extended to June 23. If you wish to submit an abstract you can do so here. Registration for in person attendance is also open. Alternatively, the talks can be viewed via livestream online for free or via a small donation.

GRCon'23 is happening in early September this year – so our submission deadlines are a bit tighter than usual.

Submission for talks, papers, workshops, and other contributions are accepted through the GRCon'23 website:


This call for participation closes on 5 June 2022! [Now extended to June 23]

A tiny bit about the GNU Radio conference:

GRCon is GNU Radio's annual conference, being held in changing cities in the U.S., and also live-streamed and chat-interacted online. Watching the main track online and interacting with the audience and speakers via chat are free. Registration for the in-person event started in March.

GRCon'23 happens 5 – 9 September in Tempe, Arizona at ASU.

What GRCon offers is a main track of presentations with topics on GNU Radio, applications of SDR / high-rate signal processing, computational radio science, scientific and industry developments, policy and technological breakthroughs.

Next to that, there's tutorials on specific topics, a poster session, Special Interest Groups and the developer's summit, which is the get-together for the project developers.

Oh, and of course, there's social events, happening at local highlight locations.

If you have *any* question (and I mean that – we're trying to make GRCon as accommodating as possible) about GRCon, be it about attendance, online participation, content submission or other problems related to the conference, we want you to reach out: Here on the mailing list, on the chat (https://chat.gnuradio.org), or in a private email to the GRCon organizers ([email protected]).


A GNU Radio DCF77 Time Signal Decoder

DCF77 is a long wave time keeping signal transmitting at 77.5 kHz from Frankfurt, Germany. It has been active since 1 January 1959. Using simple amplitude modulation, the signal encodes the current time and date, which is used by some devices like railway station clocks in Germany. Because it's a long wave signal transmitting at 50kW, it's possible to receive the signal across Europe, and sometimes even further away if propagation conditions are good.

Recently a DCF77 receiver and decoder program based on Python and GNU Radio has been uploaded to GitHub by henningM1r. It includes a simulator written in Python so you can simulate your own DCF77 signal for testing the receiver too.

Currently the decoder has been tested to work with an Airspy HF+ Discovery SDR, but it should work with any SDR capable of receiver 77.5 kHz if the GNU Radio source block is changed out.

DCF77 GNU Radio Decoder

GNU Radio Conference 2022 Talks Available on YouTube

During September 26 - 30 GNU Radio Conference 2022 was held in Washington DC. GNU Radio Conference (aka GRCon) is an annual conference centered around the GNU Radio Project and community, and is one of the premier software defined radio industry events. GNU Radio is an open source digital signals processing (DSP) tool which is used often with SDRs.

A few days ago videos of all the presentations were released on their YouTube channels, and all the talks can be found on this playlist. The videos contain a mix of in person and remote talks. A schedule of all talks can be found on the GNU Radio website.

GRCon22 - GNU Radio Project Update

Running GR-GSM and IMSI Catcher on a Raspberry Pi 4 with Dragon OS

DragonOS is a ready to use Ubuntu Linux image that comes preinstalled with multiple SDR software packages. The creator Aaron also runs a YouTube channel showing how to use the various packages installed. 

In his latest video Aaron tests his Pi64 image with GR-GSM and IMSI Catcher running with the GNU Radio 3.10 platform on a Raspberry Pi 4. He tests operation with an RTL-SDR and LimeSDR.

GR-GSM is a GNU Radio based program capable of receiving and analyzing mobile GSM data. We note that it cannot decode actual messages without additional information about the encryption key, but it can be interesting to investigate the metadata. GSM is mostly outdated these days, but still used in some areas by some older phones and devices. IMSI Catcher is a script that will record all detected GSM 'IMSI' numbers received by the mobile tower which can be used to uniquely identify devices.

Short video setting up and testing GR-GSM on DragonOS Pi64 w/ GNU Radio 3.10 and the RTL-SDR. The current DragonOS Pi64 build has GNU Radio 3.8 and all the necessary tools to accomplish what's shown in this video. If you'd like to test the build shown in this video, it's temporarily available here until I finish and put it on Source Forge.


A LimeSDR and DragonOS Focal's Osmo-NITB-Scripts was used to create the GSM900 lab environment. The RTL-SDR was able to see and decode the GSM900 network and although only briefly shown in the video, the IMSI Catcher script works.

Here's the fork used for this video and for testing. There's also a pull request on the main GR-GSM repo for this code to be added.


DragonOS Pi64 Testing GR-GSM + IMSI Catcher w/ GNU Radio 3.10 (RTLSDR, Pi4, LimeSDR, OSMO-NITB)

New GNU Radio Beginners Tutorials Available

A new set of beginners tutorials for the GNU Radio platform have been released on the GNU Radio Wiki.  GNU Radio is an open source development toolkit for signals processing and is commonly used to build software demodulators and decoders for Software Defined Radios including the RTL-SDR.

The tutorials lead you through topics such as understanding flowgraphs, creating custom Python blocks, using DSP blocks, GNU Radio core mechanics, modulation and demodulation and more.

We are pleased to announce a new set of beginner-level tutorials, as well as a new tutorials landing page, you can check them out here

A big thank you to NumFOCUS for sponsoring the work and to Matt from wavewalkerdsp who did the bulk of the work!

These beginner-level tutorials walk a new user through starting GRC and creating a simple flowgraph, all the way up to creating custom blocks and using tags and message passing.

We would like to create follow-up tutorials that the GNU Radio community needs so please leave feedback in the Discuss tab of the main Tutorials page, here are some suggestions:

  • Do you have ideas for future tutorials you’d like to see made?
  • What doesn’t make sense in GNU Radio, or what is hard to understand?
  • Where are the sticking points? What is hard to remember?
  • What is hard to use?
  • Are there any points in the current tutorials you’d like to see in more detail?
  • What would you change about the tutorials?

You can also access the tutorials using the Tutorials link on the left hand sidebar of the GNU Radio wiki, from any page.

GNU Radio Tutorial Topics

If you're interested in these tutorials you might also want to check out Michael Ossmann's set of video tutorials for the HackRF, which features GNU Radio usage heavily.

GNU Radio Conference 2021 Talks Now Available on YouTube

The GNU Radio YouTube channel has recently finished uploading the talks from GRCon21, this years annual GNU Radio Conference. GNU Radio is an open source development toolkit for signals processing and is commonly used to build software demodulators and decoders for Software Defined Radios.

The GNU Radio conference talks are generally about cutting edge SDR research topics and the YouTube playlist contains 67 videos covering a gambit between what changes have been made in new releases of GNU Radio to presentations and demonstrations focusing on topics such as reverse engineering smart power meters and 5G cell detection among many others.

Some of the talks from this years conference that we found most interesting include:

GRCon21 - Keynote: Joe Gibbs Racing Team