Technical training specialist DreamCatcher has launched a training course with LimeSDR-powered lab kit, designed to teach university-level students Long Term Evolution (LTE) network concepts.
“The ME1130 serves as a ready-to-teach package for in-depth understanding and hands-on experience on LTE and LTE-Advanced technologies,” DreamCatcher explains of the hardware that backs the course. “The PC-based implementation of LTE’s eNodeB [Evolved Node B] and EPC [Evolved Packet Core] is a powerful platform for students to explore LTE protocols and learn how to build a stand-alone LTE network.”
The hardware itself combines a compact PC with a LimeSDR USB for LTE eNodeB base station operation plus a LimeSDR Mini for spectrum analysis tasks. All are housed together on a custom-built acrylic plate, supplied in a metal box for transportation and storage.
More information on the courseware and hardware can be found on the Lime Micro blog.
LuaRadio 0.6.1 has been released, marking the software’s first update for 2020 – and bringing with it a range of fixes and improvements, including improvements to its documentation.
Designed as an alternative to GNU Radio, LuaRadio aims to offer a lightweight embeddable flow-graph signal processing framework built on LuaJIT. Like GNU Radio, LuaRadio offers source, sink, and processing blocks tied to a simple application programming interface (API) for defining and running flow graphs, blocks, and data types. Its key selling point: A compiled binary footprint of under 750kB, including LuaJIT, and a lack of external hard dependencies.
LuaRadio 0.6.1, the first release of 2020, brings with it a number of changes to block operations – including fixes for manual gain warnings appearing when using the UHDSource in auto-gain mode, crashes in the SoapySDRSource and SoapySDRSink blocks, improved library and executable discovery in the project’s Makefile, and more detailed debug dumps. The documentation has also been improved, with new examples, a simplified installation guide, and updated hardware and software suggestions for beginners on the website.
The latest version is available on the project’s GitHub repository now, under the permissive MIT Licence.
CENOS, better known for its software to simulate induction heating systems, is branching out into antenna simulation – and is looking for beta testers for its FEM simulation package.
“CENOS mission is to make simulation software affordable for every engineer. To pursuit this goal, we leverage the use of the best open-source tools & algorithms combined with simple user experience and our developer expertise,” the company claims. “We believe that simulation software should not be limited to expert users only, understandable UX, built-in templates, fast learning curve and premium support are our top priorities.”
The CENOS Antenna Designer tool, currently Windows-only. is designed to work for a variety of antenna types through a four-stage process: the user draws the antenna geometry or imports a design from a CAD package; defines frequency and bandwidth, feeds, substrate, symmetry, and other boundaries; the software then calculates 3D directivity, gain, efficiency, and S-parameters; and offers the ability to analyse the results and iterate the design.
Interested parties can sign up on the CENOS website.
Radio amateur EA7HVO has published a build guide for an antenna controller for three magnetic loop antennas, powered by the open-hardware Arduino Uno microcontroller.
“This project is for those ham amateurs who don’t have a commercial one. It’s easy to build with a soldering iron, a plastic case and a little knowledge of Arduino,” EA7HVO writes. “The controller is made with budget components you can find easily in Internet (~€20). The main component is a CNC shield that fits over an Arduino Uno. Both made a compact, small and cheap controller. This controller can work without end-stop switches because you can manually control the 0 position and the upper limit.”
The design includes support for three antennas, optional end-stop switch support, an auto-zero function, a 64,000-step range for all three antennas with micro-stepping capability, three memory banks with 14 programmable slots, an individual upper limit for each antenna, and backlash compensation.
A full guide is available on Instructables.
Researchers at Tsinghua University have designed a new aerodynamic sabre-shaped antenna which can switch between two different radiation patterns, as a means of boosting signal quality for unmanned aerial vehicles (UAVs).
“Conventional sabre-like antennas generate a donut-shape radiation pattern, which provides an omnidirectional coverage and is ideal for air-to-ground communication,” researcher Zhijun Zhang explains in an intervieq with IEEE Spectrum. “However, a donut-shape pattern has a null at its zenith.”
The solution: a new design featuring two metal radiators, a monopole and a dipole. The monopole offers the omnidirectional donut-like coverage of earlier antenna designs; the dipole covers in the blind-spot. “The two radiators not only generate two working modes and desired radiation patterns, but also provide a bonus capacitor loading effect, which shrinks the antenna size,” says Zhijun. “The antenna can switch between two modes on the fly, and thus provides top hemisphere coverage.”
More information is available in the IEEE Spectrum piece, including a link to the paper.
Ham Radio 2.0’s Jason Johnston has published a video that could prove invaluable for anyone looking to get involved in the SatNOGS project: a three-and-a-half-hour getting-started guide, based on presentations given at the TAPR Digital Communications Conference 2019.
Launched in April 2014 as part of the NASA SpaceApps Challenge and now maintained by the Libre Space Foundation, SatNOGS – the Satellite Networked Open Ground Station – project aims to create a network of satellite ground stations based entirely on free and open source software and hardware.
Getting started with SatNOGS can be daunting to a beginner – and that’s where Jason’s video comes in. “The Sunday Seminar is somewhat like the ‘anchor’ topic of the entire weekend of the TAPR Digital Communications Conference,” he writes. “In 2019 we had the privilege of hearing from Corey, KB9JHU and Dan AD0CQ from the SatNOGS Team and they are going to give us, in detail, instructions for setting up a home satellite station.”
The resulting video is available on the Ham Radio 2.0 YouTube channel.
Engineering consultancy company Mahlet has released an open-source bitstream visualisation and analysis tool called Hobbits, made available under the MIT Licence.
“Hobbits is a software platform for analysing, processing, and visualising bits,” the company explains of the software. “The Hobbits GUI is the central tool of the platform, and will be the primary focus of this document. However, the configurability and extensibility of the analysis and processing parts of the platform make it an attractive option for “headless” operation (e.g. a command line utility, or an analysis/processing server.)
“Hobbits was developed to accelerate manual data analysis tasks that were starting to burden Mahlet’s hardware and software development. The de facto solution involved the use of multiple tools with slow turnaround and improvised integration (e.g. custom Python scripts and xxd.) Hobbits provided a fully integrated analysis environment without sacrificing flexibility. As a result, it has quickly accumulated success stories across the different development teams.”
The tool is available now from Mahlet’s GitHub repository.
The Institute of Navigation (ION) has officially approved a metadata standard for Global Navigation Satellite System (GNSS) software, and has made it available for free download.
“In recent years there has been a proliferation of software defined radio (SDR) data collection systems and processing platforms designed for Global Navigation Satellite System (GNSS) receiver applications or those that support GNSS bands,” the ION Working Group responsible for the standard explains. “For post-processing, correctly interpreting the GNSS SDR sampled datasets produced or consumed by these systems has historically been a cumbersome and error-prone process. This is because these systems necessarily produce datasets of various formats, the subtleties of which are often lost in translation when communicating between the producer and consumer of these datasets.
“This specification standardises the metadata associated with GNSS SDR sampled data files and the layout of the binary sample files. The GNSS SDR Metadata Standard defines parameters and schema to express the contents of SDR sample data files. The standard is designed to promote the interoperability of GNSS SDR data collection systems and processors. The metadata files are human readable and in XML format. A compliant open source C++ API for reading metadata and binary samples is also officially supported to promote ease of integration into existing SDR systems.”
The standard is available to download now from the ION website.