TECHNOLOGY FOCUS
The hands on course teaches the key concepts of digital radio technology via practical exercises using real hardware. Participants use their own laptop with all the required RF hardware and DSP software provided for use during the course.
The course demonstrates by example a complete digital radio link, covering sampling fundamentals and
sampling rate changes, digital filtering, creating a transmit signal then receiving the signal with clock
recovery and channel equalisation. Each section of the course is split into 3 parts consisting of lectures on
theory or implementation, then the actual ‘hands on’ part where the students follow prepared
experiments that implement the section topic, reinforcing the material and enhancing their learning. This
is then followed by a short discussion part to share findings and maybe add some additional theory to the
topic. A complete set of lecture notes is provided as well as notes on the various experiments to assist
and document the anticipated findings.
The course provides an ADALM Pluto SDR and an Ubuntu live USB memory stick, preloaded with all the
required software and drivers for the course. Participants boot their computer (mac, pc or linux) using
the memory stick provided and no software is installed on the participant’s computer. The 'Ubuntu live'
disk is a complete OS, self contained, with all the software installed, tested and ready to go, essentially
the computer just provides the keyboard, mouse, display and CPU to run and interact with SDR.
COURSE CONTENT
Understand the basics of DSP using real hardware rather than abstract theory
• Understand the fundamentals of sampling and the discrete Fourier transform
• How and why to filter digitally
• Define common properties of finite impulse response filters and the basics of design
• Understand the basics of digital modulation and creating a transmitter
• Appreciate the need of interpolation and decimation
• Understand receiver synchronisation and the role of signal shaping filters
WHO SHOULD ATTEND
This is a course focusing on understanding and applying key principles of digital radio concepts. It is for product developers wanting to exploit new radio ideas as well as established engineers looking to better understand the interface between digital signals and analogue RF hardware. Using a low cost development platform and open source software, the course demonstrates the now very low barrier to entry to this previously specialised area of technology.
Day 1
1) Hardware Introduction
Getting everyone to boot their computer and detect the hardware. Then use the Pluto device and
IIO Oscilloscope application to generate a 2 tone signal and observe that in the time and
frequency domains.
2) Introduction to GNU Radio Companion (GRC)
Create a broadcast FM radio receiver from GRC blocks using the Pluto Rx. Illustrates some of the
GRC visualisation tools, setting the sampling rate, seeing why rate conversion is needed and
matching data streams to the computer sound card for audio output.
3) Investigating Sampling
Understanding the tradeoff between sampling rate, number of bits, noise and bandwidth. Along
the way observing alias signals, applying decimation and the need for filtering.
4) Digital FIR Filters
Basic design, calculating taps and applying them to the FIR hardware inside Pluto. Then use GRC
for further investigations, creating realistic signals and observing the effect of filtering.
Day 2
1) Interpolation
Demonstrating how to increase the sample rate while restricting the bandwidth. Looking at RRC
and other filtering approaches for digital modulation.
2) Transmitting
Generate digital data streams, mapping data to symbols and some basic digital modulation.
Observing the potential bandwidth of raw digital data and the need for a smarter approach.
3) Creating a QPSK Data Link
Using Pluto to both transmit and, via an RF loop back cable, receive a digital data signal.
Integrating that with GRC to observe the signal processing steps in both transmitter and receiver.
4) Receiver Synchronisation
Further investigate the QPSK link to understand details of the GRC blocks that perform timing
recovery and channel adaption.
Said about the course from previous participants:
"Extraordinary broad technical oriented systems overview."
"It was related to reality. A lot of examples. Useful hints, links. Presented tools that can be used for radio designing."
"Not only the dry math, but visually anchored (pictures, diagrams) etc."
"Getting insight into the more recent developments of radio design."
"Gives insight (many pictures / animations using the tools/black board) into the theory of radio."