OTA: QO-100 FreeDV Transmissions, Lime-Powered 5G Testbeds, O-RAN Code, and More

Lime Microsystems has published an interview with Gerhard Burian, David Rowe, and Steve Sampson on using FreeDV Mode 2020 for transmitting digital voice via the Es’Hail-2 satellite’s amateur radio transponder (QO-100) using just 1,600 Hz of radio frequency bandwidth. “The bandwidth regulation on the [QO-100] narrow band transponder, being 2,700…

OTA: Lower-Cost LimeRFE, WSPR Experiments, LoRaWAN World Records, and More

The LimeRFE crowdfunding campaign has a new, lower-cost option: the same programmable software-defined front-end board but without the components needed to operate in cellular bands, as an alternative for radio amateurs. “We’ve had some enquiries as to whether it would be possible to make a reduced cost version of LimeRFE…
LimeRFE, in hand

Call for GSoC 2018 Students

We are delighted once again to be participating in Google Summer of Code as a mentoring organisation with the Free and Open Source SIlicon Foundation. Stefan Wallentowitz, FOSSi Foundation Director, notes “Google Summer of Code is an excellent program for students to get a stipend by Google to work on…

WM4: Advance Digital Radio

The fourth instalment of the Wireless Masterclass series has been published to YouTube and this takes a look at advance digital radio, with Dr Danny Webster exploring topics including, detecting and reducing data loss, spread spectrum, OFDM and MIMO. If you missed the previous episodes these can be found at:…

LimeSDR Made Simple Part 9: It’s a VNA Too

Welcome to the ninth episode in the LimeSDR Made Simple series. Since the first we’ve been gradually adding more tools to the SDR toolbox and if you have followed the series along, by now the operation of the LimeSDR should be well and truly demystified. Last time we looked…

WM #3: The Real Radio Link

The third instalment of the Wireless Masterclass series has now been published to YouTube and this takes a look at the real radio link, with Dr Danny Webster covering topics including the noise floor and line-of-sight link budgets, bad neighbours, and receiver and propagation effects on received signals. This is…

WM #2: The LimeSDR and LMS7002

The second video in the Wireless Masterclass series has been published to YouTube and in this Dr Danny Webster introduces the LimeSDR and takes a look at the LMS7002 FPRF architecture, covering the analogue and digital halves of the chip for both transmit and receive chains. The highly integrated…

LimeSDR Made Simple Part 7: More Than One Way – Continued

Receiving and transmitting ASK/OOK signals in GNU Radio Welcome to the seventh instalment of LimeSDR Made Simple. In this post we pick up where we left off in the previous, trying to mimic the simplest of radio devices. In the last instalment we got to a point where we could…

Wireless Masterclass Video Series

Back in March we hosted a 1-day LimeSDR workshop in London, in partnership with the BCS Open Source Specialist Group and Open Source Hardware User Group. For this Principle RF Design Engineer at Lime Micro, Dr Danny Webster, put together a series of presentations that provide an introduction…

LimeSDR Made Simple Part 6: More Than One Way…

Receiving ASK/OOK signals in Pothos and GNU Radio. Welcome to the sixth instalment of LimeSDR Made Simple. Last time we looked at transmitting and receiving ASK (amplitude shift keying) signals in Octave. However, we mostly glossed over the modulation and techniques involved. In the next post(s) we will look…

LimeSDR Made Simple Part 5: Putting Software in SDR

This is the fifth instalment of LimeSDR Made Simple and in the last we explored the software side of the software-defined radio, using the relatively simple to use dataflow programming environment, Pothos. Quite a break from the previous articles where we went into detail of the input stages of the…