Tagged: Software-defined radio

DARPA Spectrum Collaboration Challenge $2 Million Dollar Championship Video

DARPA (Defense Advanced Research Projects Agency) has recently released video from their Spectrum Collaboration Challenge Championship Event where team GatorWings took home a two million dollar prize. In the original DARPA grand challenge teams competed to produce an autonomous car that can get through an obstacle course. In this spectrum challenge DARPA poses the questions, what if there was no FCC to control the band plan, and how do we make more efficient use of a scarce spectrum?

Given those questions the goal is for software defined radios driven by artificial intelligence's created by each team to autonomously find ways to manage and share the spectrum all by themselves. The AI's are required to find ways to listen and learn the patterns of other AI SDRs using differing wireless standards all of which are competing for the same slice of spectrum at the same time. The competition asks the AI's to provide simulated wireless services (phone calls, data link, videos, images) during a simulation run with all the AI's running at once. Whichever AI is able to provide the most stable services and at the same time share the spectrum fairly with the other AI's wins.

On October 23, 2019, ten teams of finalists gathered to compete one last time in the Championship Event of DARPA's Spectrum Collaboration Challenge (SC2), a three-year competition designed to unlock the true potential of the radio frequency (RF) spectrum with artificial intelligence. DARPA held the Championship Event at Mobile World Congress 2019 Los Angeles in front of a live audience.

Team GatorWings from University of Florida took home the $2 million first prize, followed by MarmotE from Vanderbilt University in second with $1 million, and Zylinium, a start-up, in third with $750,000.

Throughout the competition, SC2 demonstrated how AI can help to meet spiking demand for spectrum. As program manager Paul Tilghman noted in his closing remarks from the SC2 stage: "Our competitors packed 3.5 times more wireless signals into the spectrum than we're capable of today. Our teams outperformed static allocations and demonstrated greater performance than current wireless standards like LTE. The paradigm of collaborative AI and wireless is here to stay and will propel us from spectrum scarcity to spectrum abundance."

The highlights video is shown below, and the full two hour competition stream can be viewed here

Highlights from the Spectrum Collaboration Challenge Championship Event

The competition was run on the DARPA Colosseum, the worlds largest test bed for performing repeatable radio experiments. Capable of running up to 128 two channel software defined radios with 3 peta-ops of computing power it allows experimenters to accurately simulate real world RF environments. It works by connecting special "channel emulator" RF computing hardware to each physical SDR, which can emulate any RF environment.

The SC2 Colosseum

SDR Makerspace Conference to be Held in Switzerland in November

SDR Makerspace is a community based in Greece that is run by the European Space Agency and Libre Space Foundation (who are responsible for the SatNOGS project). It provides funding and resources for Software Defined Radio based space communication projects.

On November 28-29 2019 they are holding the SDR Makerspace Conference in Payerne, Switzerland. The conference is free to register although spaces are limited.

The technical talks during the first day will be:

  • Open-Source SDR Software for Satellite Communications - Alexandru Csete
  • LimeSDR as an enabler for Satellite TV Transmissions - Dave Crump
  • How wide band data converters enable SDR in Satcoms - e2v
  • Teaching SDR: EPFL experience - Bixio Rimoldi
  • Xilinx’s adaptive solutions for SDR application - Georg Hanak
  • SDR Makerspace: Evaluation of SDR Boards and Toolchains - Sheila Christiansen
  • SDR and Amateur radio in space - Michel Burnand
  • SDR Makerspace lightning talks - Multiple Authors

The second day will consist of workshops on using SDRs for satellite communications, and on using the LimeNET Micro and LimeRFE for SDR satcom development.

Exhibitors who will be at the conference.
Exhibitors who will be at the conference.

XYNC: A Massive MIMO SDR with up to 32×32 TX/RX Channels

Back in 2017 we posted about the crowd funding of the Fairwaves XTRX, a small PCIe based TX/RX capable software defined radio that back then cost US$199 (now only the XTRX Pro is available for US$599). The XTRX is based on the same RF chips that are used in the LimeSDR and each unit has 2 x 2 MIMO (multi-input, multi-output), 120 MSPS SISO / 90 MSPS MIMO, 30 MHz to 3.7 GHz tuning range and comes with an on board GPSDO.

Recently Fairwaves have begun crowdfunding a new software defined radio called the XYNC. The XYNC is essentially a motherboard for connecting up to 16 XTRX boards together which results in an SDR with 32 TX and 32 RX channels.

If you’re working on a massive MIMO system or have a large swath of spectrum you need to monitor, XYNC (pronounced iks-sync) is right for you. XYNC builds on the success of the Octopack SDR we offered during the XTRX campaign and takes into account feedback from the original Octopack users.

You can connect two XYNC boards, either to increase the number of RX/TX channels (e.g., two XYNC Octos give you 32 TX and 32 RX channels) or to increase throughput per channel (e.g., two XYNC Quadros give you twice the throughput of a single XYNC Octo). Connecting more than two XYNC boards is also possible, but requires an external clock and 1 pps signal distribution circuitry, neither of which is provided as part of this campaign.

While advertised as low cost, the pricing is probably out of reach for most hobbyists, with the quad 8x8 unit coming in at US$4500 and the top 16 board 32x32 unit priced at US$13,000. Still, these prices are very good for a massively MIMO SDR and pricing is set to rise once the crowdfunding campaign ends in 39 days.

The XSYNC Massively MIMO SDR with up to 32x32 TX/RX Channels
The XSYNC Massively MIMO SDR with up to 32x32 TX/RX Channels

Andreas Spiess Explains Software Defined Radio in YouTube Video

Over on YouTube Andreas Spiess has uploaded a video titled "How does Software Defined Radio (SDR) work under the Hood?". The video is an entertaining introduction to how software defined radio works and begins from the beginning by explaining how basic analogue radios work with components such as modulators, demodulators, frequency generators, mixers and filters. After the basics he goes on to explain the digitization of radio signals that occurs in SDRs, and gives an introduction ADCs and how IQ sampling works.

Later in the video Andreas shows various applications for SDRs, discusses various SDRs on the market like RTL-SDR, HackRF, SDRplay, LimeSDR and PlutoSDR and introduces GNU Radio Companion and other SDR programs from our big list of software post.

How does Software Defined Radio (SDR) work under the Hood?

GR-Oscilloscope: Using an Oscilloscope as a Software Defined Radio

A modern digital oscilloscope uses an analogue to digital converter (ADC) and digital signal processing (DSP), just like a software defined radio does, so it stands to reason that with some software hacks an oscilloscope could be turned into an SDR.

To facilitate this, jmfriedt has just released his new software called "gr-oscillioscope" over on GitHub. GR-Oscilloscope allows you to use a digital oscilloscope as a software defined radio source in the latest GNU Radio 3.8. It has been tested with a Rohde & Schwarz RTO2034 and RTE1054, and should work on any RT series oscilloscope. The software works by using the VXI11 RPC protocol which is a protocol designed for connecting instruments like oscilloscopes to computers.

GR-Oscilloscope Screenshot from GNU Radio.
GR-Oscilloscope Screenshot from GNU Radio.

Signals and Bits A New SDR Podcast by the President of the GNU Radio Project

[Ben Hilburn] the president of the [GNU Radio Project] has recently started a new podcast called [Signals and Bits]. If you were unaware, GNU Radio is the defacto open source framework for implementing digital signal processing code. Without it, many SDR programs that we take for granted may have never been developed as it is responsible for a lot of community DSP knowledge and algorithm development.

This podcast is scheduled for a new release every Wednesday and will be composed in an interview style focusing on a multitude of topics from Software Defined Radio to Spectrum Enforcement, Radio Astronomy and so much more.

In the first episode Ben interviews Harold Giddings AKA Corrosive of [Signals Everywhere] where they discuss the state of Software-Defined radio and how he got started with radio communications having come from an IT/Computer Networking background.

Ben has already pre-recorded several episodes which will ensure great content is always just around the corner. Ben would love it if you could also send feedback his way over on the [Signals and Bits Twitter] page.

Ben Hilburn President of GNU Radio (Left), Harold Giddings AKA Corrosive of Signals Everywhere (Right)

Online Course: Software Defined Radio From 0 to 1

Back in March we posted about Qasim Chaudhari and his recently released book titled "Wireless Communications From the Ground Up - An SDR Perspective". The book covers advanced University level wireless topics, but he noted how he's attempted to keep the math at school complexity (although for most people we'd say it's still more at undergraduate Engineering school complexity).

Since the last post Qasim has received a lot of feedback from radio amateurs asking for a much simpler introduction to DSP concepts, without the use of University level math. Recently Qasim wrote in and noted how he's now created a set of online lectures that is intended for either professionals who want an overview of physical layer algorithms, or radio hobbyists and general technical persons who want to expand their knowledge.

The course costs US$37 (currently discounted by 20% to $29.50 via this coupon link) and has a sampling of free videos for you to watch.

A sample slide from Qasim's Lectures
A sample slide from Qasim's Lectures

DIY Software Defined Ham Transceiver With eBay Parts

YouTuber jmhrvy1947, has recently uploaded a number of videos giving an overview of how he built his own HF SDR transceiver using what he calls the “Lego build method”. The idea of the Lego build method was to build a transceiver with parts picked and pulled from eBay so that it could be easily reproduced by others. There are a few scratch made components however those designs are available on his GitHub page. The SDR only functions within about 100 kHz of spectrum at a time however for amateur radio HF work this is more than sufficient. Bare bones the radio puts out a mere 100 mW and although the output power is small, he’s made contacts up to 450 miles away using CW (Morse code). You also have the option of adding an amplifier on  your output if you are looking for more power than that. His final revision currently puts out 100 Watts.

Using modified versions of fldigi and Quisk he is able to easily work various digital modes and sync the transmitter and receiver together. The only real down side to this radio is that you must switch out your receive and transmit filters whenever you wish to operate on different bands, a process that really only takes a moment or two.

Check out his videos on the project – it’s really amazing to see what can be done with a small budget these days in radio and with how far software defined concepts have brought us.

DIY SDR CW Xcvr Project

In the video below you’ll see an explanation of the software involved in this build.

DIY SDR CW Software