026 Essentials of Radio Communications Systems

Day 1 – Fundamental Limits
The essential feature of any RF communications system is successfully detecting a small
signal against the background of noise whilst minimising the interference from other
signals and distortion. The first day introduces, or refreshes, standard concepts such as
noise figure and intermodulation (IM), showing the sources and ways to evaluate these
key concepts. It expands typical analyses with consideration of temperature,
compression and the evaluation of ADC performance in modern digital receivers. These
concepts are illustrated with practical examples and by developing a comprehensive,
multi-stage spreadsheet to solidify the calculations and better understand how the
performance of a cascade of system blocks is evaluated.

Day 2 – System Considerations
The second day describes issues associated with frequency translation, necessary to
convert the base band signal to an RF carrier for transmission, reception and
demodulation. The previous IM concepts are expanded to explain mixers with
illustrations of radio architectures using an intermediate frequency (IF) as well
important concepts associated with low IF, direct conversion and frequency translation
as part of the ADC process. There is an introduction to the RF link budget to understand
the key antenna and propagation concepts as well as channel impairments such as fading
and delay spread that lead to substantial variability in radio propagation. Also, since
filters are required at various parts of the signal chain, there is a discussion of standard
terminology, fundamental principles and ways to estimate complexity from the just
system requirements.

Day 3 – Examples of Implementation
In the final day, key concepts of modulation and access technologies are described with
relative merits illustrated by reference to established wireless standards such as
WCMDA, WiFi, LTE/5G and digital broadcast standards. Looking at these solutions helps
to illustrates the strengths and weaknesses of various approaches from basic QPSK,
through CDMA to the modern ideas using OFDM and MIMO. It shows how signals can be
designed to combating channel impairments, as well as optimising various resources such
as frequency re-use, RF bandwidth and power. Other important design choices such as
combining and sharing resources between many users and how concepts like MIMO are
used to achieve network throughputs that actually challenge the traditional idea of the
theoretical limits.

The course finishes with some perspective on the latest trends in radio communications
with a view on how they might be best utilised. It covers key concepts relating to
software defined radio (SDR) with a practical demonstration. As well as developments
such as those in, 5G / New Radio, full duplex and ideas triggered from the incredible
capabilities of the latest generation of RF ICs

Throughout the lectures, various practical tools including spreadsheets are used to
illustrate key issues and to provide information for future analysis and design. A copy of
all the Excel examples, many useful application notes, and alphabetic list of
abbreviations and other material is provided to each student on a memory stick. This is
made more accessible via an innovative wiki based hypertext structure that allows
easy access using a standard web browser.

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."