GNU Radio Conference 2023

4 Sept 2023, 09:00 → 9 Sept 2023, 19:30 US/Arizona

ASU Memorial Union (2nd Floor)

GNU Radio Conference (GRCon) is the annual conference for the GNU Radio project and community, and has established itself as one of the premier industry events for Software Radio. It is a week-long conference that includes high-quality technical content and valuable networking opportunities. GRCon is a venue that highlights design, implementation, and theory that has been practically applied in a useful way. GRCon attendees come from a large variety of backgrounds, including industry, academia, government, and hobbyists.  Offering an annual program with broad appeal, GRCon attracts a variety of participants: people new to software radio who are interested in learning more, seasoned developers ready to show off their latest work, and experts who want to keep their finger on the pulse and direction of the industry.

GRCon23 is the 13th Annual GNU Radio Conference and will be held September 5-9, 2023.

Key Dates

• March 3 - Call for Participation Open for Abstract Submissions
• March 3 - Start of Ticket Sales
• June 23 (Extended) - Call for Participation Abstract Submissions Close
• July 15 - Initial Main Track Schedule Posted
• September 5 - Conference Begins 

 

We invite developers and users from across the GNU Radio Community to present your projects, presentations, papers, posters, and problems at GNU Radio Conference 2023. Check out the Call for Participation page for more information, or submit work using the button at the bottom of this page.

GRCon23 Schedule Overview

Attendance Justification Letter

Do you need help justifying why your manager or supervisor should send you to GRCon this year? Feel free to use this example email.

Monday, 4 September

16:00 → 18:00 Other: Early Check-In

Tuesday, 5 September

08:15 → 09:00 Conference Check-in

09:00 → 09:45 Project Talk

09:45 → 10:00 Keynote: Keynote Introduction

10:00 → 10:45 Keynote: Tuesday Keynote

10:00 Keynote: Lindy Elkins Tanton

Lindy Elkins-Tanton is a planetary scientist, the Principal Investigator of the NASA Psyche mission, and Arizona State University Vice President of the Interplanetary Initiative. Her research concerns the formation and subsequent evolution of rocky planets, and processes of education for the future of society. She has led four field expeditions in Siberia.

Asteroid (8252) Elkins-Tanton is named for her, as is the mineral elkinstantonite. In 2018 she was elected to the American Academy of Arts & Sciences, in 2021 she was elected to the National Academy of Sciences, and in 2022 William Morrow published her memoir, A Portrait of the Scientist as a Young Woman. Elkins-Tanton received her B.S., M.S., and Ph.D. from MIT.

10:45 → 11:00 AM Break

10:45 → 17:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!

11:00 → 12:00 Main Track

11:00 IQEngine Project Update and Demo

IQEngine is a free and open source web-based toolkit for analyzing, processing, and sharing RF recordings. It is built on top of the SigMF metadata standard, and the canonical instance of the site running at www.iqengine.org acts as a central repository for example SigMF recordings, while being a valuable tool for signal analysis and RF/DSP education. Using IQEngine's plugin API, GNU Radio (GR) flowgraphs in "No GUI" mode can be triggered to run on the backend, with resulting IQ samples or other outputs such as signal detection/classification immediately visible on the IQEngine spectrogram interface. This allows authors of flowgraphs to quickly test functionality on a variety of RF recordings, and debug the output, all in a web browser without having to install anything. Authors of these flowgraphs and non-GR RF functions can add their function to www.iqengine.org as a plugin in order to share it with the world. This talk will go over updates to the IQEngine project since last GRCon, demo several features (including running GR flowgraphs as plugins), and present a roadmap for the next year. We will provide examples of how individuals, universities, and organizations can get involved in the project. There is an accompanying workshop where attendees will learn how to create plugins for IQEngine, as well as an accompanying paper that dives into the REST-based plugin API design and why it may be valuable for uses beyond IQEngine.

Speaker: Marc Lichtman (IQEngine)

IQEngine GRCon23 Talk by Marc Lichtman.pdf

11:30 From 4.4 to 440: Another year of USRP and UHD Updates

As in previous years, we would like to present the latest state of our USRP family and the UHD and RFNoC software stacks. One focus of this presentation will be the USRP X440, our latest SDR product, which enables unprecedented instantaneous bandwidths. We will discuss how you can use our SDR product line to capture more spectrum than ever!

Speaker: Martin Braun (Ettus / National Instruments)

NI Sponsor Talk.pdf

12:00 → 13:00 Lunch

13:00 → 17:00 Expo Hall

13:00 → 14:40 Main Track

13:00 Design and implementation of a multi-node optical wireless communication testbed for centralized configuration and adaptation of system parameters using GNURadio’s XML-RPC and ZMQ modules

Optical Wireless Communications (OWC) is one of many new and growing interests of the research community; however, a significant amount of system-level OWC research has focused on theoretical and/or simulated analysis with limited experimental validation. In order to address this concern and support experimental OWC test systems, we have previously introduced the gr-owc out-of-tree module in GNURadio, along with a detailed description of potential hardware configurations to integrate front-end OWC hardware with USRP SDR equipment. Our initial work also demonstrated the benefits of modular design in an SDR-based OWC test system where signal processing parameters can be configured for the various characteristics of different front-end OWC hardware. This prior work demonstrated point-to-point and multi-node OWC test systems, but the flowgraph parameters were mostly fixed at the time of execution.

In this article, we will introduce recent improvements that build upon our previous successes with gr-owc. Namely, we implement dynamic control and coordination of distributed OWC nodes from a centralized testbed controller. This is achieved through a combination of GNURadio’s XML-RPC and ZMQ modules to remotely modify parameters on running flowgraphs, along with bash scripts and the Secure Shell (SSH) protocol to remotely start/stop GNURadio flowgraphs at different nodes. This results in an OWC testbed architecture that is adaptable, versatile, and scalable.
To exemplify the testbed’s capabilities, we have demonstrated the application of centrally controlled subcarrier allocation for a multi-cell and multi-user OWC system implementing DC-Biased Optical OFDMA. For the purpose of performance analysis and comparison, the implementation of a centralized testbed controller has allowed for improvements in automated data collection in GNURadio. In particular, we can now implement automated packet error rate analysis for multiple scenarios (e.g., subcarrier assignments) with multiple data points for each scenario – ultimately reducing the person hours required to collect quantitative data at scale.

Beyond the benefits of automated data collection, this testbed architecture also enables many future investigations for dynamic parameter adaptation. In order to accommodate mobile devices with variable traffic load, practical multi-cell/multi-user OWC systems should be able to dynamically allocate resources amongst OWC cells and users. Our testbed architecture enables future demonstration and analysis of different techniques for interference mitigation, rate adaptation based on user demand, or inter-cell handover for mobile users. Insights gained from this experimental analysis could improve network performance in practical multi-cell/multi-user OWC systems and offer experimental validation of systems-level research existing in the literature.

In summary, our open-source testbed supports the investigation of new resource allocation techniques and iterative improvements to the baseline OWC techniques that we provide within gr-owc, fostering collaborative research and pushing the capabilities of future OWC systems. In our paper we will provide a detailed description of our testbed’s implementation and requirements for deployment, and we will highlight the potential capabilities that our testbed can enable.

Speakers: Chukwunodebem Onwuchekwa (UMass Boston), Michael Rahaim (UMass Boston)

gr_owc-GRCon_Paper-2023.09.03.pdf

SDR_OWC-GRCon_Pres_Posted.pptx

13:15 GNU Radio and the Allen Telescope Array

The Allen Telescope Array (ATA) is the world's only radio telescope built from the ground up to perform the search for technosignatures, signs of technologically-capable extraterrestrial civilizations. Hosted on the Hat Creek Radio Observatory, the ATA is comprised of 42 6.1m in diameter, offset Gregorian radio telescopes. Cryogenically-cooled dual-polarized log-periodic feeds are mounted on the ATA focus, providing a broad and instantaneous Radio Frequency (RF) coverage of 1 to 10 GHz. Analog signals from each antenna are sent over fiber to a centralized signal processing room where they get amplified, mixed, and digitized with various backends.

Shortly after the SETI Institute took over the operations of the Hat Creek Radio Observatory in 2020, GNU Radio and the SETI Institute joined forces. Since then, an SDR-based digital setup was deployed as one of the backends for the ATA that allowed amateur radio activities and experiments to be pursued on a world-class radio telescope facility.

In this talk, I will describe the Allen Telescope Array refurbishment program and the technical and scientific capabilities of the facility. I will also describe the GNU Radio backend, the activities, and the results of the said experiments.

Speaker: Wael Farah (SETI Institute)

13:45 Ad Hoc Sensor Nets used in a Rail Enviroment

My research project is based on using modulated ultra sound at high frequency in the audio
band as a way to communicate between devices located in either Shipping Containers or Hi Rail
(Road Rail) vehicles. The research stems from a UTS capstone project completed ten years ago
that investigated methods to allow shipping containers that are stacked to form Ad Hoc
networks(Parr 2010).
The problem is that shipping containers that are stacked do not allow RF signal to propagate in
the traditional way, the signal cannot pass through the metal work of the other containers and
communication with that container will be lost. If your container has precious cargo that is of
high value, requires a controlled environment such as temperature, humidity, oxygen levels,
protection from vibration, cant or a requirements to be kept correctly oriented (Horizontal)
along with information that can determine if the cargo is becoming volatile such as certain
chemicals or if there is an issue with containment, for example if there is a possibility that it
could become a biologic hazard (transporting vaccines or corona virus samples)
A shipping container radio allows containers on the inside of the stack to form Ad Hoc shipping
networks to the containers on the outside of the stack that can communicate use standard
mobile modems. This method allows the owners of the precious cargo to maintain contact and
give real time monitoring of environmental conditions in the container(Al-Obaisat & Braun
2007).
Having worked for Metro Trains Sydney, I saw a different application for this method of
communications for Hi Rail vehicles when moving in the rail corridor. These vehicles move on
metal wheels along the track during weekend possessions and during engineering hours at night
when there are no train services.
Unlike the Rollingstock which uses communication-based train control along with a signalling
system controlling their movements; the location of each train in known down to a few
centimetres. This is required so that trains sets can correctly line up with the Platform Screen
Doors allowing passengers to embark and disembark safely from the train
Maintenance vehicles are not monitored, the operations manager has no way to track their
location and is relying on the driver to report his position on the radio. Sensor data from the
tunnels, the viaduct and at station platforms would be logged as well as real time sharing and
could be beneficial allowing monitoring of CO emissions, air quality, temperature, humidity,
location and the number of vehicles that are travelling together. These vehicles would form Ad
Hoc networks through the track with each other and with the wayside at key location. These key
locations could be at cross overs, sidings or Hi Rail pads where vehicles enter and exit the rail
corridor.
The advances in software (GNU radio/Linux OS) and embedded systems such as the new
Raspberry Pi’s which have high speed powerful processors allow these devices to be developed
at a reasonable cost, operate at low power along with a compact robust design that make them
suitable for this type of application. It is now possible to utilize these advances in application
that could not have been possible 10 years ago.

Speaker: Mr Michael Alldritt (UTS Sydney)

Ad Hoc Sensor Nets used in a Rail Enviroment GRCon ver 3.pdf

14:15 Low-Cost Educational Kit for 21-cm Observations of the Milky Way

The Completely Hackable Amateur Radio Telescope (CHART) is a radio astronomy platform aimed at high school students and teachers. The project offers online tutorials and code for building an inexpensive instrument to detect the 21-cm signal from neutral hydrogen in the Milky Way. Complete parts for the project can be acquired for under $300. The base platform is intended to work out of the box for this experiment, but is easily reconfigurable for other parts and applications. The spectrometer uses the RTL-SDR module and a custom GNURadio application which can be operated via a python-based GUI. Users analyze data in jupyter notebooks. Template code is available for flagging, calibration, plotting, and similar functions.

Speakers: Ms Lindsay Berkhout (Arizona State University), Lindsay Berkhout (ASU)

BERKHOUT_CHART_TALK.pdf

14:30 Visualization of Signal Processing for Radio Astronomy

The Completely Hackable Amateur Radio Telescope (CHART), is an initiative to create a radio telescope that is both low tech and low cost, making it easily accessible to anyone. The base design is optimized to look at the Milky Way and capture the hydrogen 21 cm line. The CHART project includes a base design that consists of a cardboard telescope and an RTL-SDR module programmed with GNURadio. In a prior iteration the data capture was done using a gnuradio python script. Here we describe a new version built in GNURadio companion with the aim of improving student understanding and encouraging modification. The template in a visual programming language can be easily replicated by new users. Custom blocks simplify the signal flow , and the use of GRC makes the signal processing steps clear and provides a fun and accessible tool set for anyone interested in radio astronomy.

Speaker: Kaitlyn Ashcroft (Arizona State University)

Visualization of Signal Processing for Radio Astronomy.pdf

13:00 → 17:00 Workshop

13:00 Introductory Tutorial for SDR and GNU Radio Beginners

Tutorial aims to introduce fundamental DSP concepts and GNU Radio to new users. It consists of the following lab modules that are all based on Jupyter Notebooks.

• Lab DSP: GNU Radio will be introduced. It will be leveraged to generate mono/stereo sound, make filtering on generated sound. Sound card will be utilized to learn fundamental DSP concepts like sampling rate, aliasing, filtering (FIR, cutoff frequency, transient range, taps), decimation.
• Lab SDR: SDR hardware used throughout the labs is introduced: RTL-SDR. General purpose SDR application (SDR# or gqrx) is explored to receive samples from RTL-SDR. Spectrum monitoring (live and waterfall), demodulation is illustrated with it.
• Lab WBFM: WBFM signal may contain more than one signal: mono, stereo, sub-channels, HD, and a data channel. Flow-graphs are created to demodulate WBFM signals in GNU Radio. Mono/stereo sound, single/multi channel, real-time demodulation examples will be presented. User will also apply Python coding to demodulate WBFM signals.

Speaker: Murat Sever (TOBB ETU)

Introductory Tutorial for SDR and GNU Radio Beginners.pdf

Repo for the Introductory Tutorial for SDR and GNU Radio Beginners

13:00 → 15:30 Workshop

13:00 USRP FPGA Processing Using the RFNoC Framework

This workshop provides a tutorial on the RFNoC framework, including a discussion on its design and capabilities, demonstrations of several practical examples, and a walk-through of implementing a user-defined RFNoC Block and integrating it into both UHD and GNU Radio. The RFNoC (RF Network-on-Chip) framework is the FPGA architecture used in USRP devices, specifically the E310, E312, E320, X300, X310, N300, N310, N320, N321, X410, X440. The RFNoC framework enables users to program the USRP FPGA, and facilitates the integration of custom FPGA-based algorithms into the signal processing chain of the USRP radio. Users can create modular, FPGA-accelerated SDR applications by chaining multiple RFNoC Blocks together and integrating them into both C++ and Python programs using the UHD API, and into GNU Radio flowgraphs. Attendees should gain a practical understanding of how to use the RFNoC framework to implement custom FPGA processing on the USRP radio platform.

Speaker: Neel Pandeya (National Instruments / Ettus Research)

14:40 → 15:00 Lightning Talk Block

15:00 → 15:20 PM Break

15:20 → 17:00 Main Track

15:20 Lo and behold, no LO! Direct Sampling techniques in SDR

Most available Software Defined Radio peripherals use local oscillators (LOs), mixers and filters to move signals of interest into the desired bands and center frequencies. With the advent of more powerful ADCs and DACs, we are able to build SDRs that don't require analog components, and instead use direct sampling techniques.

However, this puts some burden on the user, because the lack of analog flexibility means that limits imposed by the theory of digital sampling become limits of the overarching SDR application. In this foundational talk, we go back over the basics of digital sampling, effects of sampling around Nyquist zone borders, and demonstrate how some typical applications may need to be restructured.

Speaker: Martin Braun (GNU Radio)

Lo and behold, no LO.pdf

Lo and behold, no LO.pptx

NI Sponsor Talk.pdf

NI Sponsor Talk.pptx

15:50 Evaluating GPP Predictors for Software Based Waveform Performance

For the software defined radio (SDR) industry, when utilizing general purpose processors (GPPs), software-based waveform developers have leveraged Moore’s law to improve waveform performance by simply moving their code to better GPPs and SDRs as they become available. However, making full use of a computer’s capabilities today is a challenging task due to increased hardware and software complexity, requiring the use of multithreading, SIMD intrinsics, and overclocking to squeeze as much performance out of a system as possible. A challenge is predicting how a software-based waveforms will perform based on published benchmarks on a GPP of interest and where the key limiters exist. This is valuable insight to determine implementation and optimization strategies for software-based waveforms. ANDRO since 2015 has developed several waveforms with in-house written C++, focusing on pushing GPP performance to the maximum, and have over time changed our software development approach in line with these new hardware advancements and insights. This paper attempts to identify key indicators of modern GPP performance for usage with waveform software. Our method is to benchmark several open-source and custom forward error correction (FEC) algorithms and software implemented communications waveforms on new consumer-grade Intel I9 and AMD Ryzen 9 multi-core desktops. This includes ANDRO optimized low-density parity check (LDPC) encoder/decoder, ANDRO digital video broadcast satellite 2 (DVB-S2) transceiver, AFF3CT LDPC and DVB-S2, and gr-dvbs2rx waveform and LDPC. We report LDPC throughput, max waveform data rate, CPU utilization, and memory usage. Findings indicate that that CPU performance has increased to the point where now memory, i.e. RAM and CPU cache, becomes a bottleneck and predictor for waveform performance and becomes the focus for optimization.

The open-source waveforms and LDPC algorithms will be referenced with exact git repository references and configuration parameters used. The ANDRO DVB-S2 waveform and LDPC encoder/decoder are not open-source but benchmarking results will be in the presentation and accompanying paper.

Speaker: William Blair (ANDRO Computational Solutions)

EvaluatingGppPredictorsGrCon2023.pdf

EvaluatingGPPPredictorsPaper.pdf

16:05 Automatic Classification of FEC

This talk sheds light on the significantly under-explored field of automated classification of Forward Error Correcting (FEC) codes. The task, analogous to automatic modulation, determines the type of FEC code employed by examining variable-length sequences of bits. Furthermore, the objective extends to estimating vital properties of the code, including but not limited to the coding rate and block size.

Our discussion will commence with an overview of a range of popular FEC schemes utilized in diverse wireless protocols. We will delve into the technicalities of encoding with Polar codes, Turbo codes, Convolutional codes, Low-Density Parity-Check codes, BCH codes, and others. The emphasis will be on visualizing the unique characteristics of these algorithms and enhancing understanding through illustrative representations.

Subsequently, we will pivot to the core challenge of identifying and estimating the properties of FEC codes from a given sequence of bits. Our approach combines traditional methods, like computation of low-weight codewords via randomized algorithms or Information Set Decoding, and data-driven techniques using machine learning models.

In particular, the presentation will explore employing a graph-based approach for classification. We will discuss how to construct several graphical representations from captured code words, such as estimating the Tanner graph and treating each codeword as a node and their Hamming distances as edge weights can result in a graph that visually represents the relationships between codewords, thus providing insights into the underlying FEC code.

Our exploration utilizes a challenging dataset to demonstrate the practical applications of these techniques. This dataset and baseline models will be released at GNURadio Con. The findings and information in this talk will benefit novices in software-defined radio and protocol analysis by providing a comprehensive introduction to FEC codes, as well as seasoned signal reverse engineers seeking to expand their toolkits.

Speaker: Rafael Turner (Dedrone)

GNURadioTalk.pptx

16:35 GNU Radio realization of Waveform Co-design for Joint Radar-Communications system using SDRs

Combining Software Defined Radios (SDRs) with the GNU Radio software development toolkit can enable rapid prototyping of integrated sensing and communications (ISACs) systems. In this paper, we conduct a Hardware-In-The-Loop (HWIL) over-the-air (OTA) experiment on a low-cost SDR platform testbed to demonstrate the feasibility of cooperative waveform design for a joint radar-communications system. We implement the system using USRP (Universal Software Radio Peripheral) B210s and ADALM-PLUTO Active Learning Module (PlutoSDR) with GNU Radio acting as command software for the SDRs. A joint radar-communications node acts as a monostatic radar trying to detect a real target in the environment, while also acting as a communications relay. A separate SDR is transmitting a complete Orthogonal Frequency Division Multiplexing (OFDM) signal that is implemented completely in GNU Radio. The joint radar-communications SDR, equipped with high gain horn antennas, simultaneously performs radar processing to detect a real target in the environment and decoding of a communications message. MATLAB is used to implement the receive signal processing chain. Different inner modulation schemes for the OFDM communications transmitter, such as BPSK; QPSK; and 16-QAM, are also implemented to verify the soundness of the joint radar-communications system.

Keywords—ISACs, GNU Radio, Waveform Co-design, Optimization, USRPs

[1] School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ 85287.
[2] Center for Wireless Information Systems and Computational Architectures (WISCA), Arizona State University, Tempe, AZ, 85281, USA.

Speaker: Shammi A. Doly (Arizona State University)

fullpaper_grcon23_JRCs_shammi.pdf

shammi_grcon23.pptx

17:00 → 19:00 Social: Meet and Greet

Arizona Heritage Center Website

Wednesday, 6 September

08:10 → 09:00 Conference Check-in

09:00 → 09:45 Keynote: Wednesday Keynote

09:00 Invited Talk: Constantine Balanis

Constantine Balanis is a member of the Emeritus College and had been with ASU's School of Electrial, Computer and Energy Engineering (formerly Department of Electrical Engineering) since 1983, where he was a Regents Professor. His research interests are in computational electromagnetics, smart antennas, antennas, microwaves, and multipath propagation.

He received in 2004 an Honorary Doctorate from the Aristotle University of Thessaloniki, the 2005 Chen-To Tai Distinguished Educator Award from the IEEE AP Society, the 2000 IEEE Millennium Award, the 1996 Graduate Mentor Award, Arizona State University; the 1992 Special Professionalism Award from the IEEE Phoenix Section, the 1989 IEEE Region 6 Individual Achievement Award, and the 1987-1988 Graduate Teaching Excellence Award, School of Engineering, ASU. Balanis is a Life Fellow of the IEEE, Distinguished Lecturer for the IEEE Antennas and Propagation Society, and editor for the Morgan & Claypool Publishers series on "Computational Electromagnetics" and on "Antennas and Propagation".

09:45 → 10:00 Project Talk

09:45 GR3: Technical Update

10:00 → 10:45 Keynote

10:00 Invited Talk: Dr. Ralph J. Steinhagen

Dr. Ralph J. Steinhagen, a senior scientist at FAIR (Facility for Anti-Proton and Ion Research), has worked in the fields of accelerator physics and technology for over 25 years. Drawing parallels between large-scale scientific research and team sports, he cherishes having "scored critical goals for the team", especially with his contributions to feedback control and high-frequency beam RF instrumentation at CERN’s LHC, instrumental in the discovery of the Higgs Boson.

Recognised by institutions such as the Swiss Confederation, IEEE, and APS, he enjoys a hands-on approach to science and technical leadership in fostering global collaborations.

Dr. Steinhagen leads feedback design and system integration activities at FAIR, where his team is deeply committed to GNU Radio. He ardently supports the transformative journey of GNU Radio 4.0 on a technical level, aiming to position it at the forefront of software-defined radio (SDR) applications.

Speaker: Dr Ralph J. Steinhagen (GSI Helmholtzzentrum für Schwerionenforschung GmbH)

PDF Printout

presentation source files

Standing on the Shoulders of Giants - GNU Radio 4.0 Usage at FAIR

10:45 → 11:00 AM Break

10:45 → 17:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!

10:45 → 17:00 Expo Hall

11:00 → 11:45 Main Track

11:00 WSDR - web based SDR platform for learning, hacking and callobaration

Our project aims to ease SDR workflow since there are a lot of burdens especially for new beginners. Software installation, configuration might be discouraging. So we decided to do everything in a web browser.

It's possible to talk to hardware directly in a web browser using WebUSB.
WebUSB technology is available in the Chrome browser—under Linux, Windows, MacOS, and Android—without requiring specific drivers or software. But we need to do a lot of DSPs as well. Thanks to WebAssembly and the Emscripten project, it's possible to write (and even reuse) code in languages like C, C++, Rust, Go, or C# and easily port these applications to the web. WebAssembly supports its own SIMD instructions that will be translated to native vector instructions. Web Workers can serve you as processing threads, using all advantages of modern multi-core CPUs. Later adopted WebGPU standard allows even direct computation on GPU in a browser, that allows even running machine learning over TensorFlow.js natively.

We adopted these technologies into our WSDR platform. We incorporated a C-based DSP function for filtering, modulation, demodulation and wrote a javascript based scheduler and visualizer. Simple applications can be described in a flowgraph-like description with a minimal JS. However, more complex applications are possible.

To demonstrate this we ported osmocom-based 2G cellular network. It wasn't straightforward but we managed to get it stable even if running on 10 year old laptops. Special technique required to mitigate inaccuracy of web browser task scheduler. We run all BTS related staff directly on the browser leaving BSC/MSC in the cloud. But it's also possible to have a completely autonomous network running in a browser. You don't even need a laptop since it's running well on modern smartphones. This is very interesting for a swift network deploying in a disaster recovery when you have only an inexpensive SDR.

Since we're doing it in a browser we can easily collaborate and share. We also made device sharing mode, where one can share an SDR and everyone in the world can get access to it with just a click.

For researchers and education easy access to recordings is beneficial. In WSDR it's possible to connect to a data cloud provider (Azure is the only at the moment) to store, share, modify and tag recordings in SigMF format.

Using data streams sharing you can stream data to and from other legacy software. We made a special gr-wsdr block, where you can interact with the WSDR directly inside the GNU Radio.

Since we're doing it in a browser we can easily collaborate and share. We also made device sharing mode, where one can share an SDR and everyone in the world can get access to it with just a click.

For researches and education easy access to recordings is beneficial. In WSDR it's possible to connect to data could provider (Azure is the only at the moment) to store, share, modify and tag recordings in SigMF format.

Using data streams sharing you can stream data to and from other legacy software. We made special gr-wsdr block, were you can interact with the WSDR directly inside the GNU Radio.

Speaker: Andy Avtushenka

11:30 Sponsor Talk: Analog Devices

11:45 → 12:00 Lightning Talk Block

12:00 → 13:00 Lunch

13:00 → 14:45 Main Track

13:00 BLADE: The Allen Telescope Array CUDA-accelerated Real-Time DSP Library

The Allen Telescope Array (ATA) is a radio interferometer currently composed of 42 antennas. The array is made up of 6.1-meter diameter offset Gregorian telescope elements distributed randomly with a maximum baseline of 300 meters. The recently upgraded cryo-cooled log-periodic antenna feed (known as Antonio Feed) is sensitive to a wide and continuous range of frequencies ranging from 900 MHz to 12 GHz.

BLADE (Breakthrough Listen Accelerated DSP Engine) is a C++20 GPU-based computer software developed in-house to process data produced by the array. It is being used in production at the Allen Telescope Array to combine signals received by individual antennas to synthesize the aperture of a large antenna, a technique known as “beamforming”. Moreover, BLADE is also capable of post-channelize the beam-formed data into high-resolution (<1.0 Hz/bin) spectrogram in real-time. Currently, a twenty-antenna multi-beam observation routine produces a 60 GHz of complex 8-bit integer stream of aggregated data that is processed (beamformed and channelized) in real-time.

In this talk, I'm going to discuss how a software-defined telescope with a GPU-enabled processing backend can enable new scientific capabilities. As well as how to overcome hardware bottlenecks with software and important technical considerations involved in building a distributed pipeline capable of processing a stream of ~1 Tbps of data faster than real-time. The focus will be given on how the modular interface containing the Digital Signal Processing code implements optimization techniques in the background without developer input. Examples of techniques automatically applied to the module without added complexity are CUDA Graphs, a just-in-time compilation of CUDA kernels, smart parallel batch processing, and smart heterogeneous memory management.

Speaker: Luigi Cruz (SETI Institute)

BLADE GNU Radio Conference.pdf

13:30 Beamforming Using Volumetric Arrays and Computer Vision

Three-dimensional antenna arrays are a less-explored family of aperture distributions when compared to linear and planar topologies. This is due in part to performance degradation from shadowing and scattering when the array spacing is fixed and on the order of a half wavelength, but the overall logistical complexity of their construction also creates challenges that have limited their practicality. However, when the spacing increases and becomes dynamic (e.g., a distributed swarm or cluster of UAVs) the array becomes sparse and unstructured. This may also include an unpredictable and morphing spatial distribution and orientation of elements in the array. All of this combines to create a complex three-dimensional manifold with unique performance attributes that enable the use of beamforming techniques not typically leveraged in uniform planar and linear arrays.

This talk will present the design and operation of Medusa 2.0, a new array test-bed designed to evaluate the performance of beamforming algorithms for stochastic array topologies with time-varying spatial distributions. It features a computer vision system to determine the position and orientation of (up to 32) elements that are used for hybrid (analog and/or digital) beamforming and algorithms to maximize SINR, SNR, etc. in the presence of interference. This includes a various GUI elements for visualization of the array and its directivity as the array morphs and/or the beamforming algorithm converges to an optimal solution. All of these steps take place in GNURadio, highlighting the ease of creating out-of-tree modules for many different applications that may not traditionally be associated with GNURadio.

Speaker: Bailey Campbell (Penn State University)

GRCon2023 1.pptx

14:00 Implementation of Software-Defined Antenna and Radio Test System for Congested Spectral Environments

Reconfigurable narrowband antennas with operating frequency agility can provide several performance benefits like size compactness, improved noise performance, and suppression of out-of-band interferences. However, much of the research effort has focused on observing the hardware capabilities, and antenna reconfiguration is rarely implemented with a software-defined radio (SDR). The hardware/software modularity of an SDR testbed provides an opportunity to adapt the signal processing parameters along with the antenna configuration, enabling a test system capable of demonstrating/analyzing the performance impact of reconfigurable antennas on modulated data streams. Accordingly, we are developing an SDR-based platform to test the performance of tunable antennas in a modern communication environment.

From a hardware perspective, the antenna’s operating frequency is continuously tuned using piezoelectric linear actuator motors that vary the overall capacitive loading of the passive antenna. The linear actuators are controlled using external software, which converts the electrical signal to a mechanical movement of the actuator. As a preliminary step of testing the system, we are using the GNURadio software to automate the antenna’s tunability alongside a modulated data stream. In this paper, we will describe our efforts towards the co-configuration of a GNURadio OFDM signal processing flowgraph and the front-end antenna’s operating frequency, which also impacts the operating bandwidth. We will describe our test configuration and analysis of a 3-node system with Tx and Rx nodes using the reconfigurable antenna design and a third interfering node. The interfering node is set to generate various out-of-band signals that would negatively impact the primary link’s performance without proper anti-aliasing. This test setup will highlight the value of this narrowband filtering within the antenna structure in order to mitigate aliasing issues from the out-of-band interference without the need for additional hardware associated with anti-aliasing filters.

In summary, our key contributions to this paper include the development of an SDR-based test bed to characterize the performance of a tunable narrowband antenna within a modern communication channel. Furthermore, the hardware/software modularity of the SDR platform is utilized to automate the antenna’s frequency reconfiguration within the GNU-Radio framework.

Speaker: Dr Michael Rahaim

Reconfigurable_Antenna-GRCon_Paper-2023.09.01.pdf

SDR_Recon-GRCon_Pres.pptx

14:15 Phased Array FMCW Radar using the "Phaser" and GNU Radio Companion

In this talk we will demonstrate how to build, control, and process data from a 10 GHz, 8 element, FMCW phased array radar. We will be using Analog Device's open source CN0566 (aka "the Phaser"), the ADALM-PLUTO, and GNU Radio Companion. There will be a live demonstration of beamforming fundamentals including: direction of arrival, monopulse tracking, tapering, grating lobes, and FMCW radar. We will also highlight the advantages of using GRC vs Python. All of this is fully open source, with readily available hardware and software posted at wiki.analog.com/phaser

Speakers: Jon Kraft (Analog Devices), Mark Thoren (Analog Devices)

Phaser_with_GRC_Sept4_2023.pdf

13:00 → 15:00 Workshop

13:00 O-RAN 5G Network with srsRAN

The srsRAN Project provides an open-source, ORAN-native, 5G CU/DU solution to simplify OpenRAN and 5G research, development, and testing.

srsRAN supports the use of 3rd-party UEs and 5G Cores (5GCs) to create end-to-end 5G networks with ease, with the option to fully customize the implementation. A great example of this is the ability to easily deploy a network and connect COTS UEs for everything from private 5G networks to R&D for security with nothing more than a USRP and a 3rd party 5GC. Recent months have seen the addition of support for O-RAN radio units (O-RUs) in srsRAN through our new Open FrontHaul (OFH) implementation. OFH is a portable, easy-to-use library for O-RAN fronthaul with minimal third-party dependencies. This has opened up opportunities for new users, use-cases and allows new players into the O-RAN development space. To aid with making E2E testing as seamless as possible, for everything from 5G to O-RAN-centric use cases, we have authored multiple tutorials that clearly explain how to implement these networks.

In this workshop we will go through these use cases in detail, showing how to bring up these networks from start to finish. The workshop will detail and explain the necessary hardware, configurations, and steps to connect devices to the srsRAN gNB to create seamless E2E 5G and O-RAN networks. We will also provide an update on the current project status and a development roadmap for the coming releases.

Speaker: Brendan McAuliffe (Software Radio Systems)

13:00 → 15:00 Workshop

13:00 Building Basic Data Transmission Systems with GNU Radio

In this workshop, we'll constructively go through building a simple transmitter and receiver system for a basic modulation scheme, starting from a clean-sheet GNU Radio companion window.

During development, design considerations will be explained, to close the gap to classical digital communications design theory.

The workshop will require participants to have a working GNU Radio 3.10 installation on their own laptop. A bootable x86_64 Linux USB drive image will be offered.

The target audience is users who have used GNU Radio before, but not intensively, or new users. Some DSP basics will be helpful.

Speaker: Marcus Mueller

14:45 → 15:00 Lightning Talk Block

15:00 → 15:20 PM Break

15:05 → 17:05 Workshop

15:05 Introduction to Signal Processing

This course introduces and surveys beginner and intermediate-level signal processing focused on communications systems. The course will introduce basic math concepts fundamental to and applications of signal processing. The course will explore the properties of signals and systems, including spectral estimation, detection, and information theory.

Speaker: Wylie Standage-Beier

15:20 → 16:50 Main Track

15:20 Ultra-wideband SDR architecture for AMD RFSoCs using PYNQ based GNU Radio blocks

The AMD RFSoC (Radio Frequency System on Chip) architecture has gained significant attention within the Software Defined Radio (SDR) community for its integration of Radio Frequency (RF) frontend, FPGA fabric and Linux-capable Arm-based processing system. Despite its accessibility to researchers via the RFSoC2x2 and RFSoC4x2 development board platforms, its adoption within the GNU Radio community has been limited. This work demonstrates the potential of combining RFSoC with GNU Radio. We aim to enable wider use of RFSoC in the GNU Radio community by targeting a reference system to the low-cost RFSoC4x2 board, which comes with open-source full-stack software. This paper presents a novel design that leverages the Quad Small Form-factor Pluggable (QSFP) network interface to establish an up-to-100GBit/s bi-directional data link between GNU Radio, running on a personal computer (PC), and the RFSoC4x2 for arbitrary radio signal transmission and reception. Due to the high speed RF-ADCs (5 GSPS) and RF-DACs (9.85 GSPS) found on the RFSoC platform, a QSFP network interface is necessary to facilitate transmission of signals generated off-board. We have developed a small library of reusable, PYNQ-based GNU Radio Out of Tree (OOT) modules that allow interfacing with the FPGA fabric, RF ADCs and DACs. Using the remote procedure calls we are able to control the Tx/Rx centre frequency and RFSoCs Digital Up/Down Converter (DUC/DDC) rates from the host PC to achieve runtime configurable bandwidth. Additional signal inspection and visualisation is implemented using existing GNU Radio GUI widgets and analysis blocks.

Speaker: Mr Marius Siauciulis (University of Strathclyde)

gr_with_rfsoc.pdf

15:35 Employing GNU Radio for Robust Testing of the Novel DASH SoC

Through the patronage of the DARPA DSSoC program, we constructed the DASH SoC, a coarse-scale heterogeneous SoC that breaks the trade-off in computational efficiency versus ease of reprogrammability. The DASH SoC caters to the target domains of sophisticated RF processing for communications, radar, PNT, and spectral situational awareness. We also developed an FPGA-based DASH emulation platform to showcase the capabilities of the DASH SoC and aid in rapid testing and validation. In this paper, we use GNU Radio to rapidly test and validate the functionality of the DASH SoC’s custom FEC accelerators with real data. We generate a realistic communications transmit chain with LDPC encoding in GNU Radio, and then feed the resulting output into the DASH SoC emulation framework to perform LDPC decoding via the FEC accelerator. We will show the results of the LDPC decoder and showcase the functionality of the DASH SoC. Through GNU Radio, we can develop realistic communications transmit chains that scale up in complexity with great ease, enabling us to rapidly and robustly test the DASH SoC

Speakers: Drake Silbernagel (Arizona State Graduate Student - WISCA/Bliss Labs), Prithvi Hemanth (Arizona State Graduate Student - WISCA/Bliss Labs), Saquib Siddiqui (Arizona State Graduate Student - WISCA/Bliss Labs), Alex Chiriyath (Arizona State University)

grcon2023DashFecOtaTest.pdf

grcon_lpdc_dash_emulator_2023.pdf

15:50 Phase coherence in Radio Interferometry: using, and measuring, White Rabbit with GNU Radio

Radio telescopes are some of the largest instruments in use in astronomy, but their (angular) resolution is actually somewhat poor. This can be improved upon by combining several radio telescopes, in a technique called radio interferometry. This creates a much larger virtual radio telescope, with its size (and resolution) determined by the longest distance between participating telescopes. For radio interferometry to work, the signals need to be captured against a stable reference clock at each station. If the reference clocks aren't stable enough, this will reduce the achievable sensitivity of the whole system.

White Rabbit is an open hardware system for the accurate transport of time and frequency signals over fiber. It was originally designed at CERN for controlling the Large Hadron Collider, but is now in use in many instruments in particle physics and astronomy.

We are researching the use of White Rabbit as a reference distribution system for radio astronomy. In particular, we have measured the phase noise of several types of White Rabbit links, and used this to quantify the suitability of White Rabbit for clock distribution in radio interferometry. We then created a mock radio interferometer using SDRs and GNU Radio, to verify these predictions. Finally, we demonstrate the use of White Rabbit and GNU Radio in radio interferometry during astronomical observations.

Speaker: Paul Boven (JIVE/CAMRAS/U. Leiden)

16:20 SETI Institute

Speaker: Simon Steel

15:20 → 16:50 Workshop

15:20 SigMF Workshop

The Signal Metadata Format (SigMF) specifies a way to describe sets of recorded digital signals with metadata written in JSON. It was designed for RF recordings, which consist of IQ samples. SigMF can be used to describe general information about the RF recording, the characteristics of the system that generated the samples, and features of the signal itself. This workshop, hosted by two of the SigMF leads (Jacob and Marc), is meant to be informational and include discussion with participants. It will include:

• Quick intro to SigMF for new people (Marc)
• Project update, including state of SigMF within GNU Radio (Jacob)
• Short tutorials
  1. Make your IQ into SigMF with notepad, how does SigMF help me (Marc)
  2. I built tooling that processes IQ, how can SigMF help me (Marc, using Inspectrum as a case-study)
  3. Using SigMF within GNU Radio (Jacob)
  4. Creating a new SigMF extension (Jacob)
• Prerecorded demo from Airbus (3 mins)
• Open discussion and questions

Speakers: Jacob Gilbert, Marc Lichtman

17:05 → 17:50 Breakout Session

Convener: Samantha Palazzolo

17:05 Women+@GRCon Meetup

A chance for women (and others!) attending GRCon to meet up. Very informal.

18:30 → 20:30 Other: Breakthrough Listen SETI Reception

Thursday, 7 September

08:15 → 09:00 Conference Check-in

09:00 → 09:45 Keynote: Thursday Keynote

09:00 Keynote: Eric Blossom

Eric Blossom founded the GNU Radio project in 2001 and ran it as a full-time undertaking through 2010. Eric was responsible for the original architecture and implementation of GNU Radio, including the fundamental concepts of blocks, streaming data, the buffering system, and the first two generations of schedulers. If there's something about GNU Radio that bugs you, there is a good chance that Eric is to blame.

He is deeply grateful for all of the people who have used and supported GNU Radio over the years and particularly to those who have worked to evolve it into a more powerful and useful tool. Eric has spent the last 6 years at Planet Labs, one of the leading "new space" companies, building a family of high speed radios used to downlink imagery of earth from Planet's constellation of satellites. These satellites are in a 500km orbit, and the radios downlink imagery at > 1.5Gb/s, totaling terabytes of data per day across the constellation.

09:45 → 10:45 Project Talk

09:45 The Road to GR 4.0

Much effort has been put towards what will become the official GR 4.0. In this brief overview, we discuss the various aspects of the prototypes and plans for the future.

Speaker: Josh Morman

10:00 GNU Radio 4.0: Standing on the Shoulders of Giants -- An Overview of New Features and Significant Enhancements

The upcoming GNU Radio 4.0 release (GR4) will be the latest evolution of GNU Radio, signifying a marked advancement from GNU Radio 3 and a path to long-term, broad adoption of the framework. GR4's development prioritises streamlining the codebase by removing extraneous complexities inherited from its predecessor while preserving valuable functionalities. This approach enhances the software radio platform's adaptability, flexibility, and maintainability.

The critical focus of GR4 is to maximize performance across heterogeneous platforms while lowering entry barriers for new contributors. This minimises cognitive complexity and provides a more manageable learning curve. Doing so nurtures a more inclusive ecosystem where academics, industrial partners, and students can actively contribute and innovate.

The Facility for Antiproton and Ion Research (FAIR), in collaboration with other entities, leverages its expertise in high-performance computing, Research Software Engineering (RSE), real-time signal processing, diagnostics, and feedback systems to introduce a transformative feature set for GR4. This work fundamentally alters the underlying runtime and development paradigm, embracing a more modern and sustainable framework that forms the core of GR4. The prioritisation of type safety underpins this work, along with reduced overhead and a more user-friendly and extensible design.

Key features of GR4 include high-performance, type-safe, lock-free IO buffers; zero runtime overhead for certain sub-graphs; portable SIMD support; and tag-based timing system integration for nanosecond-level synchronisation. Moreover, it introduces transactional settings updates, expands continuous signal processing to support synchronised packet data processing, provides cross-platform support, and offers a pluggable work scheduler architecture adaptable to different execution domains and scheduling constraints.

GNU Radio 4.0 is under pre-production testing at FAIR, involving a large-scale deployment across hundreds of nodes to verify its full-stack capabilities and resolve any teething problems. Preliminary results indicate a ten-fold improvement in throughput and runtime performance.

We invite early adopters to explore, test, and use this new version of GNU Radio. As we strive to foster collaboration and knowledge exchange across industries, academic institutions, and government organisations, we present this talk to highlight the comprehensive advantages and improvements of GR4. For anyone engaged in software radio technology, this exploration of GNU Radio 4.0 promises valuable insights.

Speaker: Dr Ralph J. Steinhagen (GSI Helmholtzzentrum für Schwerionenforschung GmbH)

GNU Radio 4.0: Standing on the Shoulders of Giants (PDF, expanded)

GNU Radio 4.0: Standing on the Shoulders of Giants (PDF, Print)

GNU Radio 4.0: Standing on the Shoulders of Giants (Slides)

10:45 → 11:00 AM Break

10:45 → 17:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!

10:45 → 17:00 Expo Hall

11:00 → 11:45 Main Track

11:00 Polymorphic Types of the Future

Over the past few years, we have been working to rewrite the Polymorphic Types (PMTs) used in GNU Radio. The current PMTs can be confusing and difficult to use. The new PMTs use modern C++ to provide a simple and efficient interface. This new library will replace the current implementation in GNU Radio 4.0.

There have been a few twists and turns developing this new library and it has been completely rewritten over the past year with significant performance improvements.

In this talk, we will show how to install and use the new PMT library and some of the exciting new features, such as automatic conversion to and from C++ structs. We will include benchmarks for several common operations showing the improvements over the current PMT library. Lastly, we will show some of the ways that PMTs are being used in GNU Radio 4.0.

Speaker: John Sallay

GrCon23 - Pmt.pptm

11:00 → 12:00 Workshop

11:00 IQEngine Workshop

Note - This is a hybrid workshop / hacking session

• Brief introduction to the IQEngine project
• Follow-along tutorial for how an existing GNU Radio flowgraph can be modified and containerized to be run as an IQEngine plugin
• Chat about pipelines
• Discussion on the REST-based interface design that IQEngine created to run plugins, and how it can potentially be useful beyond IQEngine, as an open interface for running RF functions in a non-realtime manner
• How to get set up with a dev env for IQEngine plugins on your machine

This workshop is (roughly) estimated to be 1h in duration, and no hardware is required.

IQEngine is a free and open source web-based toolkit for analyzing, processing, and sharing RF recordings. It is built on top of the SigMF metadata standard, and the canonical instance of the site running at www.iqengine.org acts as a central repository for example SigMF recordings, while being a valuable tool for signal analysis and RF/DSP education. Using IQEngine's plugin API, GNU Radio (GR) flowgraphs in "No GUI" mode can be triggered to run on the backend, with resulting IQ samples or other outputs such as signal detection/classification immediately visible on the IQEngine spectrogram interface. This allows authors of flowgraphs to quickly test functionality on a variety of RF recordings, and debug the output, all in a web browser without having to install anything. Authors of these flowgraphs and non-GR RF functions can add their function to www.iqengine.org as a plugin in order to share it with the world.

Speaker: Marc Lichtman

IQEngine Workshop.pptx

11:45 → 12:00 Lightning Talk Block

12:00 → 13:00 Lunch

13:00 → 17:00 Amateur Radio License Exam

13:00 → 15:00 Main Track

13:15 Behind CyberEther: Metal Hardened Portable GPU Accelerated Interface

This year's talk will focus on the progress made in the development of CyberEther since last year's presentation. Software development has progressed significantly, and it's time for a new update. We will discuss the latest features and improvements, including brand-new DSP acceleration on Metal (inside Apple Silicon’s GPU) and support for Vulkan which makes it possible to use CyberEther on Linux. The software has reached a point where it can run natively on both iPhone and iPad devices. I will also share the development roadmap for future CyberEther updates and its integration with GNU Radio. Attendees will learn how CyberEther can improve their signal processing tasks and how they can easily implement it in their applications. A live signal-oriented demo will be presented to showcase CyberEther's capabilities. During this demonstration, attendees will have the opportunity to witness the power of CyberEther in action and see how it can be applied to solve tasks.

CyberEther provides a GPU-accelerated frequency sink interface, including 2D Waterfall, Lineplot, and Spectrogram displays. It utilizes modern graphical APIs such as Metal and Vulkan. Its internal Digital Signal Processing (DSP) is accelerated using parallel computing APIs like CUDA, Metal, and Vulkan whenever possible. CyberEther is modular, allowing it to adapt to the target device and run with the best-supported combination possible. On an Apple Silicon device, CyberEther leverages Metal for both graphical and compute processing. Meanwhile, Raspberry Pi users can expect Vulkan for graphical processing and VkFFT for DSP, while Linux desktop users will find CyberEther using Vulkan for graphical processing and CUDA for DSP.

The CyberEther interface is written in modern C++20 and is portable. It can be easily implemented in an application with minimal changes. The interface has minimal core dependencies and acceleration and graphical modules are loaded only if all dependencies are available at compilation time, which avoids dependency issues.

This talk will also demonstrate CyberEther as a GNU Radio out-of-tree module and explain how the internal DSP works. The development process and tips for optimizing heterogeneous computing will be shared.

Speaker: Luigi Cruz (SETI Institute)

GNU Radio Conference 2023 - CyberEther REL.pdf

13:45 The Future of Spectral Use

Speaker: Prof. Dan Bliss (ASU - WISCA)

14:15 High Accuracy Wireless Timing Synchronization Using Software Defined Radios

Timing synchronization plays a critical role in many high performance software defined radio applications. However, currently, to achieve the level of synchronization required to perform distributed open loop beamforming, cabled techniques such as precision PPS fanout buffers or White Rabbit must be used to align the system clocks to within a small fraction of a sample. However, we have recently presented techniques to achieve picosecond-level synchronization wirelessly for distributed phased array beamforming accomplished using the RF front-end on Ettus X300 software defined radios. This talk will address the waveform design, time delay estimation and refinement process, and software implementation strategies used to achieve this high level of performance using host-controlled processing in GNU Radio.

Speaker: Jason M. Merlo (Michigan State University)

2023_grcon_merlo.pdf

2023_grcon_merlo.pptx

13:00 → 16:00 Workshop

13:00 Embedded SDR Workshop - Overview of differences and skills needed for Embedded SDR

UPDATE: Download the large file:
https://www.dropbox.com/scl/fi/7qg5ek6g3pgruf1m1a0z6/sstate-cache.tar.gz?rlkey=jempcarxo0gctymrkw54pfzx8&dl=0
in order to be able to build packages during the workshop.
This workshop will cover aspects of using Embedded SDRs, including benefits and limitations. The workshop will begin with an overview of differences between Embedded SDR’s vs. Radio front-ends that are designed for use with a larger computer. The workshop will then focus on applications that demonstrate GNU Radio use of embedded SDR. Intermixed with the applications will be discussions of skills, jargon, and information needed to maximum the use of an embedded SDR. Topics covered will include basic Yocto/Openembedded, low-level Linux control of hardware, definitions of common Embedded terms, descriptions of buses, device-trees, and low level Linux kernel control among others. There will be a few radios available to use during the workshop, most likely around 5. A laptop with Linux as the main operating system will be required to use the radio. A laptop with preinstalled GNU Radio 3.10.x would allow the attendee to work with a few more examples.

Speakers: Philip Balister, Toby Flynn (Red Wire Technologies, LLC)

14:45 → 15:00 Lightning Talk Block

15:00 → 15:20 PM Break

15:20 → 17:05 Main Track

15:20 TorchSig Update

TorchSig, a toolkit for applying deep-learning applications to wireless signals, was released last year and presented at GRCon. The toolkit has since undergone numerous changes to improve reliability and usability. This includes new examples for using deep-learning for tasks in spectrum awareness, new utilities for curating datasets, speedups in synthetic dataset generation and speedups in data augmentations.

Speaker: Garrett Vanhoy (Peraton Labs)

15:35 Amateur Radio, DSP and GNU Radio

Amateur radio has been around for almost 120 years and has traditionally contributed to advancing the state of the radio art. In the early days of the hobby, many discoveries about radio and propagation were made by amateur experimenters and helped lay the foundation of radio science as we understand it today.

Amateur contributions continued into the late 20th century, and “hams” were among the first to develop widely distributed and interoperable (if inefficient) packet radio networks, new “weak signal” digital modes and open access satellites.

Some innovation continues to this day, but the move from analog to digital radio technology presents a significant challenge to the hobby, threatening its legislative mandate.

Most hams have little background in DSP and how SDRs work, and this is having impact on the amateur’s ability to innovate in the hardware realm. The tiny percentage of amateurs who may be classified as “technologists” understand modern radio systems and continue to innovate, but the vast majority of “communicator” hams with little understanding of digital radio have been left behind and are focused on using commercial radios in support of the community and in on-air amateur radio events.

This talk will look at amateur radio's mandate, licensing requirements and the newly-emerging “technologist” versus “communicator” demographic within the hobby. It will describe how gnuradio could be used to teach DSP and SDR techniques to new and existing amateurs (especially those in the “communicator” demographic) with the goal of keeping the hobby relevant and able to continue to advance the radio art in the 21st century.

Speaker: Kevin McQuiggin

16:05 General-Purpose Phased Array Learning Kit: Efficient Interference Mitigation

This presentation introduces a versatile general-purpose phased array learning kit designed to address the critical challenge of interference mitigation in various communication scenarios. The primary focus is on showcasing the effectiveness of null steering techniques in mitigating interference caused by adjacent and overlapping channel interferers. The system features a linear phased array comprising eight antennae operating at a frequency of 10.5 GHz, provided by Analog Devices Inc. The presentation highlights the objective of showcasing the efficiency of null steering in reducing interference levels and improving communication capabilities. A carefully selected single continuous wave (CW) interferer, operating within a +/-10% range of the receiver frequency, was introduced to evaluate the system's performance. Through a combination of simulation and practical implementation, the presentation demonstrates the significant reduction of interference levels in the relevant direction by no less than 30 dB.

This presentation contributes to the advancement of phased array technology and its practical applications in communication systems. The findings underscore the significance of null steering techniques in improving communication capabilities and provide valuable insights for researchers, developers, and practitioners working in the field of interference mitigation and communication systems.

• https://www.analog.com/cn0566
• https://www.mathworks.com/videos/series/understanding-phased-array-systems-and-beamforming.html

Speaker: Robin Getz (MathWorks)

GRCon Phase Array.pdf

18:00 → 21:00 Social: Thursday Social

Arizona Heritage Center Website

18:00 GRCon23 Social @ Arizona Heritage Center

Friday, 8 September

08:15 → 09:00 Conference Check-in

09:00 → 09:30 Main Track

09:00 Receiving Faxes with GNU Radio

I will be presenting a method of receiving the NOAA weather fax system and viewing the transmission in real time using GNU Radio. This presentation will go over the process of creating a simple HF antenna, receiving HF on an RTL-SDR, how to decode APT (Automatic Picture Transmission) signals, and how to view faxes in real time. I will also touch on issues faced while creating this project, a brief history of radio facsimiles, and show some images that were received. As part of this presentation the GNU Radio implementation will be demonstrated.

Speaker: Matthew DeMorat (Oak Ridge National Lab)

09:30 → 10:15 Project Talk

09:30 Panel Discussion: GR 4.0 Next Steps

Speakers: Josh Morman, Dr Ralph J. Steinhagen (GSI Helmholtzzentrum für Schwerionenforschung GmbH)

10:15 → 10:30 AM Break

10:15 → 10:55 Breakout Session

10:15 Women+@GRCon (Part 2)

Back by popular demand by those who could attend our first gathering and those who had conflicts.

10:15 → 13:15 Workshop

10:30 GR 4.0 Block Workshop

Hands-on session to work within the new framework to develop some usable blocks for GR 4.0 and learn the new paradigm

Speakers: Alexander Krimm, Josh Morman, Dr Ralph J. Steinhagen (GSI Helmholtzzentrum für Schwerionenforschung GmbH)

20230906_GNU_Radio_Friday_handson.odp

20230906_GNU_Radio_Friday_handson.pdf

10:30 → 11:45 Main Track

10:30 File Transfer using Packet and BPSK

A project was created with the following objectives:

• Send a file without repeating it.
• Use Packet formatting.
• Use BPSK modulation.
• Provide a means for the receiver to synchronize with the BPSK before the file is sent.

The talk will present the issues faced with meeting the objectives and describe how each piece was achieved. Simulated and live transmissions will be presented.

Speaker: Barry Duggan (GNU Radio)

File_transfer_using_Packet_and_BPSK.mp4

11:00 Demodulation demonstration using the LightCube CubeSat

LightCube is a 1U Educational Cubesat which had the goal of connecting the public with space by producing a flash visible to the naked eye on command by a public user. The spacecraft could be triggered via HAM radio communications by those with an amateur license. LightCube is commanded with a DTMF sequence, and reports telemetry using RTTY, an AFSK modulation scheme. Telemetry is decoded with a custom GNURadio companion flowgraph. Several radio applications were written, including a from-scratch decoder written for educational purposes and one optimized to be compatible with the SatNOGS environment. Lightcube deployed from the international space station on April 24th 2023 and operated for 24 hours before suffering a battery failure. During this time it was tracked by many amateurs around the world with observations reported to the SatNOGs database. Audio observations of the beacons were subsequently decoded by the student team and by amateurs. Having received many observations from around the world, the team has been able to reconstruct the sequence of events leading to loss of communications.

Speakers: Lindsay Berkhout (Arizona State University), Lindsay Berkhout (ASU)

Demodulation_demonstration_using_the_LightCube_CubeSat.pdf

GRCON_LIGHTCUBE_TALK_BERKHOUT.pdf

11:15 Measuring time delays with sub-sampling period resolution: qualification of some COTS SDR RF frontends with sub-100 ps resolution

The RADAR equation states that the range resolution is inverse of the bandwidth. This generic time of flight assessment resolution under general conditions is greatly improved under the assumption of a single isolated target illuminated by a known noise sequence with a delay resolution improved by the signal to noise ratio brought by the correlation during the pulse compression.

Using pseudo-random sequence spectrum spreading over less than typical Commercial Off The Shelf (COTS) Software Defined Radio (SDR) hardware (2.5 Mchips/s BPSK modulation of a 70 MHz carrier spreading over less than 5 MHz bandwidth), we qualify the fine time delay with a resolution much lower than the sampling period. Each individual channel of dual channel receivers is observed to exhibit time delays randomly distributed within the sampling period despite the external PPS and clock being synchronized in the B210 and X310 SDR receivers, with standard deviations within each continuous acquisition in the sub-ps range. We demonstrate however that the differential delay of the X310 between both channels exhibits a reproducibility from one run to another in the sub-100 ps range whereas the complex ADi AD936x frontend of the B210 introduces fluctuations of the differential delay in the ns range. A basic experimental setup is demonstrated for reproducing the experiment on any SDR RF frontend.

Speaker: Jean-Michel Friedt (FEMTO-ST/Time & Frequency, Besancon, France)

Proceedings

Slides of the presentation

Video of the presentation

10:45 → 16:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!

10:45 → 15:00 Expo Hall

11:45 → 12:00 Lightning Talk Block

12:00 → 13:00 Lunch

13:00 → 14:45 Main Track

13:00 Wireless Signal Processing Education

Communication systems, by their nature, have a complex structure that contains multiple technologies. In order to teach communication systems, the steps that need to be taken in order for the signal to be transmitted to reach from the source to the destination are explained by prioritizing the block-based flow-graph. The given theoretical knowledge is consolidated by mostly using examples and assignments given in a selected simulation environment. However, as this method is too abstract, it can make the learning process difficult and can alienate the student from the subject. With the “Communication Educational Kit” project presented in this article, we aim to teach wireless communication with experiments in the real environment, to make theoretical knowledge long-lasting through insightful applications, and to increase the student’s software development ability. In this project, we outline newly developed laboratory coursework that supports undergraduate education through an interactive interface. It can be deployed with two different models. Host-based deployment requires installment on student’s computer; whereas standalone mode includes both hardware on which signal processing will happen and pre-installed software. This educational kit is a low-cost integrated development environment which includes open-architecture hardware and software. The educational material provides the opportunity to analyze signals with different characteristics using various open-source tools and it consists of laboratory modules which are prepared to increase the student’s engagement as well as signal processing and programming skills. The kit is unique with its following features: It is not just limited to one environment but contains general-purpose Software Defined Radio applications, Free and Open Source Software radio toolkit GNU Radio, and JupyterLab notebooks providing interactive coding environment as integral parts of the course. It is language-independent, as of now students can code either in MATLAB or Python, and also remote-ready.

Speakers: Murat Sever (TOBB ETU), Murat Sever (TOBB ETU)

WirelessSignalProcessing.pdf

13:15 Design of a 1296 MHz SDR Radio System for EME

EME or Earth Moon Earth communications requires sensitive receivers, relatively high power transmitters and signal processing to be able to communicate by reflecting a signal off the moon. This talk will discuss the system and RF design details in making an EME capable station. The topics include the system link budget, antenna requirements, detailed RF receiver and transmitter design.

The signal processing path will be discussed in detail including the auxiliary control functions for tracking and real time frequency control. Results will be shown for a functioning system.

Speaker: Dennis Rosenauer

grcon_sep_23.pdf

13:45 A brief overview of the ALBATROS cosmology experiment

The Array of Long Baseline Antennas for Taking Radio Observations from the Seventy-ninth parallel (ALBATROS) is a 21cm cosmology experiment that uses multiple autonomous antenna stations operating in the high Arctic of Canada to lay the groundwork for probing into the cosmic “dark ages” before star formation began. An overview of the ALBATROS project will be provided, along with a primer on where Software Defined Radios and open source software fit in with the tech stack of the project. Using a mix of hobbyist grade equipment, the team has managed to connect over a quarter of a petabyte of storage to a Raspberry Pi control system, allowing the experiment to take continual measurements over the arctic winter. The talk will cover existing hardware for the antenna stations and control systems, and will end with a brief overview of the new autonomous ground penetrating radar drone the team is constructing using GNURadio as a core component.

Speaker: Francis McGee (McGill University)

GRCon Talk-3.pdf

14:00 ALS162 Time Signal SDR Receiver for GNU Radio

A real-time SDR receiver of the French time signal ALS162 is studied, implemented and tested for GNU Radio. Inspired by the practical observations and the minor but yet appealing challenges encountered, this receiver provides another supportive learning exercise for practical signal processing with GNU Radio. Along with the transmitter and receiver design, the present paper addresses several commonly used signal processing concepts like signal synthesis, FIR and IIR filters, phase modulation, phase drift compensation, basic synchronization, symbol correlation, decision metrics and error detection that are applied in terms of GNU Radio.

Speaker: Henning Maier

ALS162_paper_henningM1r_GRcon23.pdf

ALS162_slides_henningM1r.pdf

14:15 Open-Source Antenna Pattern Measurement System: Collaborative Development and Applications

Weber State University (WSU) has developed an ‘open-source’ antenna-pattern measurement system physically comprised of software-defined radios (SDRs), Arduino microcontroller and 3-D printed hardware. The student-designed measurement testbed was supported by the Utah NASA Space Grant Consortium. The ‘open-source’ prototype integrates Python, GNU Radio Companion, and Linux on a single laptop PC. The system is portable and used for education- and industry-outreach.
The Python-GNU Radio Companion software is now available in a GitHub-WSU repository. Recently, a prototype was delivered/loaned to a Naval laboratory for assessment.
The following paper describes an evolving collaboration between WSU-ECE and NSWCDD-DNA. Potential applications of the prototype are discussed. In addition, the current status and future improvements of the hardware and software are detailed.

Speaker: Dr Jonathn West (WSU-ECE)

13:00 → 17:00 Workshop

13:00 Introduction to GNU Radio with Python

This workshop is a guided, hands-on introduction to GNU Radio blocks, graphs, and systems for Python users. This course will demonstrate some of the benefits of using GNU Radio for building digital receivers. It will cover more advanced concepts, including Protocol Data Units, tagged streams, polymorphic types, and development using gr_modtool. GNU Radio experience is not required. Python experience is recommended.

Speaker: Wylie Standage-Beier

14:45 → 15:00 Lightning Talk Block

15:00 → 15:20 PM Break

15:20 → 16:20 Main Track

15:20 Advancing Ground Station Capabilities: A Web-based Application with GNU Radio for Seamless Satellite Tracking and Communication

The authors present a web-based front end satellite tracking application for the automated tracking of two student-designed CubeSat satellites scheduled for launch in 2024 operating with a full duplex scheme in the UHF and commercial S-band frequency bands. Satellite signals are captured and processed by integrating GNU Radio with the Ettus Research USRP x300 SDR hardware. The USRP x300 provides the necessary bandwidth and sensitivity to track the satellites' signals and extract telemetry data. The application uses GNU Radio's signal processing capabilities to implement the DVB-S2 communication standard and the QPSK modulation scheme, ensuring compatibility and efficient communication with the tracked satellites. Challenges such as Doppler shift compensation, signal demodulation, and synchronization are addressed, enabling reliable and accurate satellite tracking. Integrating GNU Radio with external open-source software and libraries, such as GPredict, enhances its satellite tracking capabilities. This integration facilitates precise satellite position prediction, automated tracking, and communication scheduling. The satellite tracking application utilizing GNU Radio and the USRP x300 SDR showcases the potential of open-source tools in revolutionizing satellite tracking and analysis. The work presented aims to improve satellite communication, space exploration, and scientific research in the upcoming era of satellite deployment.

Speaker: Adriana Rivera (UTEP Aerospace Center)

grcon23_presentation.pdf

15:35 OFDM Based Joint Communications and Human Vital Sign Sensing with GNU Radio

This paper implements an OFDM based system for joint communications and sensing. OFDM traditionally is used for passing modulated information bits in a multi-path channel. Prior to decoding the information bits, channel state information (CSI) is extracted from multiple sub-carriers in OFDM frames. The GNU based OFDM sensing performance is compared with our prior GNU based CW radar implementation. The results shows distinct but insightful sensing performance from OFDM based and radar based implementation. The comparison study highlights the advantages and disadvantages of OFDM based human physiological signal measurement.

Speakers: Adarsh Akkshai Venkataramani (Arizona State University), Isabella Lenz (Arizona State University)

GRCon_OFDMVitals_PesentationSlides_Lenz_9_23.pptx

15:50 Introducing RSESS: An Open-Source Enumerative Sphere Shaping Implementation Coded in Rust

In this work, we present an open-source implementation of the enumerative sphere shaping (ESS) algorithm used for probabilistic amplitude shaping. Information theory shows that the capacity of an additive white Gaussian noise (AWGN) channel is reached if the input symbols follow a Gaussian distribution. However, many communication systems employ a uniform distribution of channel input symbols, and therefore a shaping gap prevents the communication system from reaching capacity. This shaping gap amounts up to 0.255 bits/channel use or translated to an increase in required SNR, this corresponds to a loss of 1.53 dB in energy efficiency. In order to obtain a certain probabilistic shaping (i.e., a non-uniform probability distribution) of the channel input symbols, a distribution matching algorithm is required to map the uniformly distributed input bits to a sequence of modulation symbols following the desired probability distribution. Distribution matchers can be implemented in various ways; in order to work well with other information processing blocks in communication systems, a block-based (fixed-to-fixed length) mapping of a fixed length input bit sequence to a fixed length symbol sequence is desired. As the number of sequences in this mapping becomes very large even for small block lengths, a simple lookup table becomes unfeasible very quickly. The mapping must therefore be performed algorithmically. One distribution matching algorithm which has gained in popularity is ESS. ESS operates on a trellis representation of a subset of the possible symbol sequences and the desired shaping rate is controlled by constraining the energy in a sequence. This leads to the empirical distribution of the symbols in the represented sequences closely approximating the optimal distribution for the AWGN channel. A lexicographic ordering approach is used on the trellis to assign a unique index to each sequence. Finally, to define a mapping from bit sequence to symbol sequence, the bit sequence is interpreted as a binary number and used as this index. It is important to note that the lookup is performed algorithmically and it is not required to store all possible transmit sequences with their corresponding index. To perform the reverse operation, the index of a received symbol sequence is constructed using the pre-computed trellis. We provide an open-source implementation of this algorithm in the compiled language Rust. This facilitates simulations using our implementation to run significantly faster than implementations in interpreted languages like Python or Matlab. For interoperability, we provide Python/NumPy bindings with which our Rust algorithm can be used from a regular Python script. We will also present simulation results on the AWGN channel and compare the results with previous works on this topic.

Speaker: Mr Frederik Ritter (KIT)

introcucing-rsess-grcon2023-paper.pdf

introcucing-rsess-grcon2023-slides.pdf

16:20 → 17:00 Project Talk: GRCon Main Track Closing

16:20 CTF Final Results

16:30 GRCon Main Track Closing

Saturday, 9 September

09:30 → 11:30 Breakout Session: Breakout Sessions

09:30 Breakout Session: GRC File Format

Speaker: John Sallay

09:30 → 15:00 Project Talk: Hands-On Day

13:00 → 14:00 Saturday Snacks

Full lunch not provided... but there will snacks!

14:00 → 16:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!