Technical proceedings from the annual GNU Radio Conference (GRCon). Focusing on Open Source, Free Software, Software Radio, Signal Processing, Radio Communications, and related open technologies!
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Enabling Integrated Circuit-Based Full-Duplex Wireless in GNU Radio
Full-duplex (FD) wireless communication, the simultaneous transmission and reception of wireless signals on the same frequency channel, has garnered significant attention from the research community over the past decade. Softwaredefined radio (SDR) has become instrumental in bridging the gap from theory to implementation, providing the flexibility necessary to design and deploy FD radio nodes, links, and networks. As part of the Full-Duplex Wireless: From Integrated Circuits to Networks (FlexICoN) project, we have developed three generations of IC-based FD radios that utilize GNU Radio as the primary control and signal processing platform. This paper presents an overview of the design considerations and techniques for implementing FD in GNU Radio, from the transmit and receive signal processing chains to broader testbed integration.
Copyright (c) 2024 Alon S Levin, Manav Kohli, Sasank Garikapati, Mahmood Baraani Dastjerdi, Harish Krishnaswamy, Gil Zussman, Igor Kadota, Tingjun Chen, Aravind Nagulu, Jin Zhou, Ivan Seskar
Communication using GNU Radio and Ultrasound Practical Application
This research is based on using modulated ultrasound at high frequency in the audio band as a way to communicate between devices located in air, liquid, containers (such as shipping) and rail vehicles. It is an alternative solution to using a traditional radio system in places where RF does not propagate well such as enclosures, or structures that obstruct the radio signals. The project was initially based on shipping containers that normally use 4G modems mounted on the outside of the containers as a way to communicate its ID along with environment data to the asset manager allowing cargo that may be sensitive to heat, humidity, vibration to be monitored. If the containers are stacked in rows adjacent to each other, the communication system can fail when the container in the middle cannot transmit a signal out of the stack or connect to the local mobile base station. Ad Hoc sensor networks can be created to allow audio communication to nodes (containers) located on the outside of the stack where that information would re-transmitted using the 4G modem that has a network connection. Acoustic communication is also a great solution in water or other liquids where radio signals degrade quickly over short distances. The GNU radio FSK solution provided some excellent results for liquids and allowed me to leverage from this to using OFDM at a later phase in steel rail. This paper focuses on modulating data through water and other liquids. The advances in software (GNU radio/Linux OS), D/A converters and micro-PCs that have fast processors allowing these devices to be sourced at reasonable cost, operate at low power along with a compact robust design makes them suitable for this type of application. It is now possible to utilize these advances in software that could not have been possible 10 years ago.
5G Base-Station with Hardware Acceleration for Non-Terrestrial Networks on a Space-Grade System-on-Chip
Delivering 5G connectivity from space to consumer hardware via Non-Terrestrial Networks serves a variety of safety and convenience usecases for consumers. This transformation of the cellular network incurs major technical changes, with space-based base stations posing the main disruption. Although a healthy competition between space companies has been sparked, technical details specifically from the satellite payload perspective, i.e., satellite processing technology and 5G stack integration, remain mostly proprietary and undisclosed, hindering system understanding, standards development, and overall research. We present a heterogeneous payload design for a completely on-board 5G base station (gNodeB) using the next-generation spacequalified VERSAL hardware, a multi-core CPU platform, and a tightly integrated RF front-end. We propose a â€processing splitâ€ by distributing 5G layers between these components and show its benefits, particularly on the example of a hardware-accelerated 5G PHY layer. A brief technology readiness assessment and a discussion on open points concludes this paper.
Copyright (c) 2024 Michael Petry, Raphael Mayr, Michael Hennerich
gr-pdw: An OOT Module for Pulse Descriptor Word (PDW) Generation
Characterization of pulsed waveforms results in measurements commonly referred to as pulse descriptor words (PDW). PDWs are often utilized for radar sensor characterization, identification, and emulation. Pulse measurements are typically provided as an option on high-SWaP, high-cost laboratory test equipment or as custom FPGA firmware which is not easily scalable to multiple SDR/RF platforms. gr-pdw is an out-of-tree (OOT) module for GNU Radio developed by GTRI that performs pulse detection and PDW generation. The intention is that grpdw provides the ability for any commercial-offthe- shelf (COTS) SDR to perform PDW measurements. Currently it is capable of measuring pulse width, power, frequency, and time-ofarrival (ToA), and signal-to-noise ratio (SNR). gr-pdw also provides blocks for writing PDWs to an HDF5 formatted log file and visualizing measurements in GNU Radio Companion. Testing has been performed with a USRP B210 in both laboratory and field settings with measurements comparable to currently used PDW generators.
Copyright (c) 2024 James "Trip" Humphries, Stan Sutphin, Brian Mulvaney, James Landreth
Implementation of a Multi-Channel DASH7 IoT Communication System for Packet Investigation and Validation
The Internet of Things market has emerged over the past decades and continues to grow. Therefore, IoT devices have become omnipresent. Many of these devices use a wireless connection to send and receive data which are based on Low Power Wide Area Network protocols. The most used LPWAN technologies are Narrowband IoT (NB-IoT), LoRaWAN, LTE-M, and Sigfox. Due to the increasing amount of IoT devices, these LPWAN protocols have become even more important. However, many of these protocols are proprietary, and therefore, it remains unknown how they exactly operate. We dive into the inner workings of one of these LPWAN protocols. More specifically, we investigate the PHY of the DASH7 Alliance Protocol (D7AP). We present a fully-fledged DASH7 communication system by using GNU Radio. The software can be used as a simulation instrument and can be applied in real-world scenarios by using low-cost Software- Defined Radios. In this way, it is possible to investigate a complete IoT transceiver system that is open-source and easily adaptable. Furthermore, it can be used to build up, investigate, and validate DASH7 data packets.
Copyright (c) 2024 Dennis Joosens, Rafael Berkvens, Maarten Weyn, Noori BniLam
Real-Time FMCW Radar System forWaveform Optimization using SDRs
We develop a highly flexible real-time FMCW radar system for designing and testing different radar waveforms (e.g., triangular, sawtooth) and radar signal processing algorithms (e.g., stretch processing) without the need for extensive hardware modifications and MATLAB codes. We implement an adaptive waveform co-design technique in a single real-time feedback loop for multi-user networks applications leveraging lowcost SDRs. To implement a feedback loop in real-time, an asynchronous message-passing interface is employed in this experiment. Furthermore, we show the benefits of radar waveform optimization, particularly by increasing RMS bandwidth and significantly increasing target detection performance by enhancing range resolution. To demonstrate real-time spectrum optimization, we use the GNU Radio block for realtime spectrum analyzer (RTSA)-like spectrum visualization.
Copyright (c) 2024 Shammi A Doly, Gerard Gubash, Mikko Heino, Alex Chiriyath, Daniel W Bliss
29 MHz LEO satellite SDR LFM radar for citizen ionospheric science
We describe a 29 MHz radar system that illuminates the ionosphere from a CubeSat in low earth orbit. The radar uses a Linear Frequency Modulation (LFM) format that matches that of the Coastal Observation Radar (CODAR). SDR receivers operated by radio Amateurs and citizen scientists running a GNURadio flowgraph are used to measure the impulse response and Doppler of the radio propagation path through the ionosphere. The system may be viewed as a bi-static radar with transmitter and receiver in different location. The measured data and metadata is uploaded to a central data repository for analysis. One of the objectives of the project is to motivate citizen scientists and radio Amateurs to learn about radar systems, ionospheric science, SDR, GNU Radio and low earth orbit satellites. The GNU Radio-related work is the development of a Toolbox for the processing of CODAR signals.
Copyright (c) 2024 Peter Driessen, Levente Buzas
TorchSig: A GNU Radio Block and New Spectrogram Tools for Augmenting ML Training
TorchSig uses machine learning (ML) to detect and classify digitized radio frequency (RF) signals. Recent updates and improvements to TorchSig are given, as well as novel features for image-only spectrogram generation and training, reducing memory and computational burdens and making training much faster. A new GNU Radio out-of-tree (OOT) block is provided which uses a TorchSig ML model for detecting signals in real-time.
Copyright (c) 2024 Phil Vallance, Erebus Oh, Justin Mullins, Manbir Gulati, Jared Hoffman, Matt Carrick
Using GNU Radio in a Multipath Environment Practical Application
Having used GNU Radio for several years, it has many worthy applications. One such use has been propagating data using ultrasound in a variety of material such as air, water and steel. The modulation protocol used to date has been binary FSK (some ASK/PSK have also been used), however these protocols do not handle multipath well. For this application we would look to use OFDM, however OFDM is normally used in a broadband application, where many subcarriers can be created, using it in an application that has limited bandwidth can be challenging. The bandwidth I have available with standard transducers is less than 1 kilohertz, as such the scaling and management of the subcarriers can be difficult. Sound waves travelling in solids can be made up of transverse and longitudinal waves, the sensors receiving this mixed signal must be able to filter out the unwanted signal so the modulated data can be extracted with the minimum number of errors. In liquids and air, shields can be employed on the receiving sensor to limit the unwanted signal picked up by the transducer, however in solids this is not possible. My objective is to modulate data in steel rail using GNU radio at a data rate that has useful and practical application. This paper explores these issues and how GNU radio can be employed to create duplex channels in ultrasound that can be used for data communications.
Design and Implementation of LoRa Physical Layer in GNU Radio
LoRa is the physical layer of LoRaWAN, one of the most popular low-power wide-area network (LPWAN) technologies for the Internet of Things (IoT). LoRa uses a proprietary chirp spread spectrum modulation. The modulation is used together with error correction coding and interleaving to achieve long-range communication with low energy consumption. In the past years, many reverse engineering attempts have been made and led to an overall understanding of the encoding and modulation scheme used by the physical layer of LoRa. In this paper, we present in detail all the signal processing operations required to transmit and receive a LoRa frame for all the modes that are supported by commercial devices. We further develop the synchronization methods used by our open-source implementation of a LoRa transceiver that is fully compatible and has been tested extensively with commercial LoRa devices. Finally, we evaluate the performance of our LoRa transceiver implemented in GNU Radio and available on GitHub.
Copyright (c) 2024 Tapparel Joachim, Andreas Burg
Ultra-wideband SDR architecture for AMD RFSoCs and 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 Linuxcapable Arm-based processing system in a single package. Despite its accessibility to researchers via the RFSoC 2x2 and RFSoC 4x2 development board platforms, its adoption within the GNU Radio community has been limited. This work demonstrates the potential of combining RFSoC with GNU Radio by utilizing a bidirectional QSFP network link to transmit and receive a wideband Orthogonal Frequency-Division Multiplexing (OFDM) signal. Using the remote procedure calls we are able to control the Tx/Rx center 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.
Copyright (c) 2023 Marius Siauciulis, Louise H Crockett, Robert W Stewart
Advancing Ground Station Capabilities: A Web-based Application with GNU Radio for Seamless Satellite Tracking and Communication
The authors present a web-based satellite tracking application for the automated tracking of two student-designed CubeSat satellites scheduled for launch in 2024 operating in the UHF and S-band frequency bands. Satellite signals are captured and processed by integrating GNU Radio with the Ettus Research USRP x300 SDR hardware. 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 open-source software and libraries, such as GPredict, facilitates precise satellite position prediction, automated tracking, and communication scheduling. The application showcases the potential of open-source tools in revolutionizing satellite tracking and analysis. Overall, this work aims to improve satellite communication, space exploration, and scientific research in the upcoming era of satellite deployment.
Copyright (c) 2023 Adriana Rivera, Keren Lozoya Flores, Joel Quintana
Time of flight measurement with sub-sampling period resolution using Software Defined Radio
Timing signal delay difference with subsampling period resolution is achieved by spectrum spreading using a pseudo-random sequence generator and fitting the cross-correlation peak of the received signal. An experimental demonstration on various radiofrequency software defined radio (SDR) receivers demonstrates sub-ps synchronization on the Ettus Research X310 BasicRX frontend, picosecond synchronization of the AD9361 fitted on the Ettus Research B210, and a drift of a few hundred picoseconds during measurements lasting a few seconds with the Lime Microsystems LMS7002 fitted on the Fairwaves XTRX. All measurements are achieved with 200 ns sampling period or a rate of 5 Msamples/s, emphasizing the timing resolution improvement of at least 1000-fold over the sampling period.
Copyright (c) 2023 J M Friedt, G Goavec-Merou
Software-Defined Radio Based Feedback System for Beam Spill Control in Particle Accelerators
Controlling stored beams in particle accelerators requires specially designed RF signals, such as needed for spill control via transverse excitation. The software-defined radio (SDR) technology is adopted as a low cost, yet highly flexible setup to generate such signals in the kHz to MHz regime. A feedback system is build using a combination of digital signal processing with GNU Radio and RF Network-on-Chip (RFNoC) on a Universal Software Radio Peripheral (USRP). The system enables digitization of signals from particle detectors and direct tuning of the produced RF waveforms via a feedback controller – implemented on a single device. To allow for triggered operation and to reduce the loop delay to a few ms, custom OOT and RFNoC blocks have been implemented. This contribution reports on the implementation and first test results with beam of the developed spill control system.
Copyright (c) 2023 Philipp Niedermayer, René Geißler, Rahul Singh
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 constellation shaping (PCS). PCS aims at closing the shaping gap caused by using uniformly distributed modulation symbols in channels for which information theory shows non-uniformly distributed signaling to be optimal. ESS is one such PCS algorithm that sets itself apart as it operates on a trellis representation of a subset of the possible symbol sequences. ESS leads to an empirical distribution of the symbols that closely approximates the optimal distribution for the additive white Gaussian noise (AWGN) channel. We provide an open source implementation of this algorithm in the compiled language Rust, as well as Python bindings with which our Rust code can be called in a regular Python script. We also compare simulation results on the AWGN channel using our implementation with previous works on this topic.
Copyright (c) 2023 Frederik Ritter, Andrej Rode, Laurent Schmalen
Implementation of Software-Defined Antenna and Radio Test System for Congested Spectral Environments
Research in Software Defined Radio (SDR) is often focused on the software aspects related to digital signal processing for agile radios. However, the front-end hardware plays a significant role in the overall performance of SDR networks. In dynamic and adaptive radio systems, static antenna design can greatly limit the system’s performance potential. Reconfigurable narrowband antennas offer an opportunity to enable fullsystem software control with the ability to jointly configure the software-based signal processing chain along with the configuration of the frontend antenna. In this article, we present initial work towards the development of a GNURadiobased test system for SDR and reconfigurable antennas. Furthermore, we introduce our opensource GitHub repository, gr-recon, which provides example scenarios for use of the New Scale Pathways software tool to remotely configure distributed GNURadio flowgraphs and front-end reconfigurable antenna hardware.
Copyright (c) 2023 Rosalind Agasti, Elliot Kim, Jessica Ruyle, Chukwunodebem Christopher Onwuchekwa, Shabnam Azizi, Michael Rahaim
Design and Implementation of a Multi-Node Optical Wireless Communication Testbed for Centralized Configuration and Adaptation of System Parameters using GNU Radio’s XML-RPC and ZMQ Modules
Over the past two decades, Software Defined Radio (SDR) techniques have allowed the RF community to bring many wireless communications topics and educational tools from theory and simulation to experimental test systems. In our work, we have brought these capabilities to the field of optical wireless communications (OWC). In this article, we discuss key capabilities for extending our prior work to multi-cell and multi-user OWC systems with centralized configuration and control. These capabilities are enabled by GNU Radio and introduced within the gr-owc out-oftree library. We highlight how these capabilities are being applied for automated data collection and how the work enables future opportunities in systems-level research for OWC networks.
Copyright (c) 2023 Chukwunodebem Christopher Onwuchekwa, Maryam AminuMukhtar, Lenny Martinez, Ashley D Lemus, Victoria Planchart, Fedor Y Semash, KC Kerby-Patel, Honggang Zhang, Micheal B Rahaim
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 and 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.
Copyright (c) 2023 Lindsay M Berkhout, Christopher McCormick, Daniel C Jacobs, Jaime Sanchez de la Vega
Employing GNU Radio for Robust Testing of the Novel DASH SoC
Through the patronage of the The Defense Advanced Research Projects Agency (DARPA) Domain-Specific System-on-Chip (DSSoC) program, we constructed the Domain-focused Advanced Software-reconfigurable Heterogeneous (DASH) system-on-chip (SoC), a coarse-scale heterogeneous SoC that breaks the trade-off in computational efficiency versus ease of reprogamability. The DASH SoC caters to the target domains of sophisticated RF processing for communications, radar, positioning, navigation, and timing (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 Forward error correction (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 are able to develop realistic communications transmit chains that scale up in complexity with great ease, enabling us to rapidly and robustly test the DASH SoC.
Copyright (c) 2023 Drake Silbernagel, Prithvi Hemanth, Alex Chiriyath, Saquib Siddiqui, Wylie Standage-Beier, Daniel Bliss
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-TheLoop (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 with GNU Radio acting as command software for the SDRs. A joint radar-communications node acts as a mono-static radar trying to detect a target in the environment, while also acting as a communications relay. A separate SDR transmits a complete BPSK or QPSK modulated signal that is implemented completely in GNU Radio. The joint radar-communications SDRs, equipped with high gain horn antennas, simultaneously performs radar processing to detect an emulated target in the environment and decoding of a communications message. Different modulation schemes for the communications transmitter, such as BPSK and QPSK are also implemented to verify the soundness of the joint radarcommunications system.
Copyright (c) 2023 Shammi A Doly, Alex Chiriyath, Wylie Standage-Beier, Daniel W Bliss
Evaluating GPP Predictors for Software Based Waveform Performance
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 general purpose processor (GPP) of interest and where the key limiters exist. This is valuable insight to determine implementation and optimization strategies for software-based waveforms. This paper attempts to identify key indicators of modern GPP performance for usage with waveform software, using LDPC and DVB-S2 waveform benchmarks on two consumer grade desktops. We find a correlation in software performance between GPP or memory reliance and GPP clock speed and cache, as well as the importance of system tuning and overclocking.
Copyright (c) 2023 William “BJâ€ Blair, Ashwin Amanna, Timothy Reichert, Michael Gudaitis
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
High-Speed Sensing of the Electromagnetic Environment for Cognitive Radio Receivers
In this paper we demonstrate an EM environment aware (EMEA) radio called the Intelligent Transceiver Radio Node (ITRN) that is suitable for use in cognitive radio applications. The ITRN is an end-to-end solution that can quickly find interferers and act upon them in a defensive manner such as filter, move the channel, move to different band, etc. While the ITRN is capable of finding interferers in both the spectral dimension, we present a framework that allows for future expandability into more measurement domains. To break to sensing time tradeoff with spectral and angular resolution, we employ the use of compressed sensing (CS). By making a few assumptions on the local EM environment’s current state, we are able to perform spatial and spectral scans that are a factor of 10 times faster than the current state of the art. Information on the spectral locations of the interferers, along with a current QoS estimate is then sent to a machine learning based decision engine (MLBDE) where reinforcement learning is used to determine the optimal channel selection. For the ITRN’s sensor, we use a custom 8 antenna RF-ASIC fabricated in TSMC 65nm CMOS called the Direct Space to Information Converter (DSIC). The output of the DSIC is sent to an Ettus X310 radio. A custom UHD interface was constructed in the field programmable gate array (FPGA) to speed the streaming data rate by using a variable data packet size. Custom UHD circuitry was also created to synchronize the DSIC with the clock on the X310. In GNU Radio, we perform the baseband DSP and Orthogonal Matching Pursuit (OMP) which is used to recover the spectral locations of the interferers. Lastly, the output of OMP along with a QoS estimation is sent to the MLBDE which calculates the new optimal channel selection and retunes the ITRN.
Copyright (c) 2022 Matt Bajor, Ron Li, Con Pappas, Elliot Olsen, David Thuel, Steve Pizzo, Petar Barac, Peter Kinget
Large Scale Radio Frequency Signal Classification
Existing datasets used to train deep learning models for narrowband radio frequency (RF) signal classification lack enough diversity in signal types and channel impairments to sufficiently assess model performance in the real world. We introduce the Sig53 dataset consisting of 5 million synthetically-generated samples from 53 different signal classes and expertly chosen impairments. We also introduce TorchSig, a signals processing machine learning toolkit that can be used to generate this dataset. TorchSig incorporates data handling principles that are common to the vision domain, and it is meant to serve as an open-source foundation for future signals machine learning research. Initial experiments using the Sig53 dataset are conducted using state of the art (SoTA) convolutional neural networks (ConvNets) and Transformers. These experiments reveal Transformers outperform ConvNets without the need for additional regularization or a ConvNet teacher, which is contrary to results from the vision domain. Additional experiments demonstrate that TorchSig’s domain-specific data augmentations facilitate model training, which ultimately benefits model performance. Finally, TorchSig supports on-the-fly synthetic data creation at training time, thus enabling massive scale training sessions with virtually unlimited datasets.
Copyright (c) 2022 Luke Boegner, Manbir Gulati, Garrett Vanhoy, Phillip Vallance, Bradley Comar, Silvija Kokalj-Filipovic, Craig Lennon, Robert D Miller
Passive reception of Two-Way Satellite Time and Frequency Transfer (TWSTFT) signals from a geostationary satellite, or GPS upside down
We explore the reception of signals emitted by European time and frequency metrology Observatories and broadcast by a geostationary satellite by processing signals recorded from a consumer television reception parabola using a software defined radio.
Novel Implementation of a Keyless Concurrent Codes Spread-Spectrum (CCSS) Jam-Resistant Method in GNU Radio
Current omnidirectional jam-resistant technology relies on shared secrets. This forces private networks to exchange keys before jamming is present and leaves public networks (like GPS or ADSB/Mode-S) unprotected. Given the proliferation of inexpensive Software Defined Radios (SDRs), robust jam-resistant options are more important than ever. This project implements the “BBCâ€ codec–a keyless, concurrent codes spread-spectrum (CCSS) strategy–in GNU Radio. Initial testing of the BBC codec confirms theoretical performance estimates and suggests that BBC is a viable option to preserve information availability. Development is underway to provide an out-oftree (OOT) module for broader use within the GNU Radio community.
Copyright (c) 2022 James Morrison, Neil Rogers, William Bahn
Implementation of Faster-than-Nyquist Signaling using Software Defined Radios
In this paper, we consider the development and implementation of a faster-than-Nyquist (FTN) signaling system using a binary phase-shift keying modulation (BPSK). We present a review of the theory and pertinent historical works related to the FTN signaling scheme, as well as practical work carried out in a laboratory environment. The popular open-source, and radio-specific, signal processing application GNU Radio was used to develop transmitter and receiver architectures. These architectures were then deployed for execution on various software-defined radio (SDR) hardware. We have evaluated the minimum Euclidean distance (MED) and probabilistic data association (PDA) estimators performance in terms of bit-error-rate (BER). We observed for higher noise variance to achieve a BER of 10^−3 with τ = 0.8 when using MED and τ = 0.9 when using PDA.
Copyright (c) 2022 Gregory Dzhezyan, Michel Kulhandjian, Hovannes Kulhandjian
Respiratory and Heart Rate Detection Using Continuous-Wave Radar Testbed Implemented in GNU Radio
Demand for non-contact health monitoring devices has motivated a variety of radar-based vital sign measurement techniques. To demonstrate these techniques, we implement a simple respiratory and heart rate monitor using GNURadio and a commercial-off-the-shelf (COTS) softwaredefined radio (SDR). This implementation executes a Doppler-only, bi-static, continuous-wave radar application using an Ettus X310. We use GNURadio signal processing blocks to execute a simple respiratory and heart rate detection algorithm that extracts these vital signs from a subject within the radar’s field of view. In several experimental trials, we demonstrate that the proposed technique successfully extracts the respiration rate and estimates the heart rate to within ± 5 BPM of a traditional heart rate monitor.
Copyright (c) 2022 Isabella Lenz, Jacob Holtom, Andrew Herschfelt, Yu Rong, Daniel Bliss
GNU Radio and CEDR: Runtime Scheduling to Heterogeneous Accelerators
Accelerators in GNURadio have been previously limited to requiring the selection of an accelerator framework/block at design time. In this paper, we present a preliminary investigation into supporting two new capabilities with GNURadio: first, we illustrate the ability to execute GNURadio blocks across a variety of heterogeneous accelerators (FPGA and GPU). Second, we demonstrate that we are able to dynamically schedule these blocks across our pool of accelerators using easily-customizable scheduling policies. We do this via a combination of out-oftree modules and by embedding GNU Radio itself as an application in a heterogeneous runtime called CEDR (Mack et al., 2022). The CEDR ecosystem provides a productive environment for researching the combined challenges of application design, systems software, and hardware prototyping for heterogeneous systems, and namely, it provides a flexible intelligent scheduling (IS) interface by which the user can easily adjust or prioritize how tasks are dispatched at runtime to the various accelerators present on a given system. The IS integrates a variety of runtime schedulers that optimize for metrics such as application performance and minimum scheduling algorithm overheads. The IS in tandem with CEDR improves the performance of applications through dynamic scheduling by efficiently utilizing the resources at runtime.
Copyright (c) 2022 Joshua Mack, Serhan Gener, Ali Akoglu, Jacob Holtom, Alex Chiriyath, Chaitali Chakrabarti, Daniel Bliss, Anish Krishnakumar, Alper Goksoy, Umit Ogras
Open-Source Antenna Pattern Measurement System: SDR-based Student Research and Development
Weber State University (WSU) has developed an ‘open-source’ antenna-pattern measurement system physically comprised of software-defined radios (SDRs) and 3-D printed hardware. The present WSU ‘open-source’ prototype integrates Python, GNU Radio Companion, and Linux on a single laptop PC. Multiple student projects have investigated methods to improve measurement fidelity in non-optimal environments. For example, excellent agreement between measured and simulated radiation patterns has been obtained using coherent AM detection. The following paper summarizes the development of the current system and presents results from student research.
Copyright (c) 2022 Matthew Finger, Taylor Hansen, Christian Hearn