ABSTRACT
Data throughput is one of the end-user’s most important performance parameters for a communications link. This tutorial systematically explores the trade-offs between distance, power, antenna size, frequency, bandwidth, and modulation complexity and shows their impact on the data rate that can be achieved.
Shannon’s equation is a simple equation relating bandwidth, power, and noise to system capacity, and is a good starting point. The link budget equation can then be added to provide a high-level picture showing the effect of distance and antenna gain on the receiver threshold and transmitter capability. Using both, the concept of fade margin can be developed and related to further choices in modulation and bandwidth, so that the data rate and associated error rate can then be determined.
Comparisons between terrestrial and satellite communications are used to illustrate the key principles. Finally, typical commercial radio system architectures for both terrestrial and satellite terminals are shown and simulated to illustrate how system imperfections, such as linearity and noise, can degrade the bit error rate and link performance, and to show why poorly designed systems are more susceptible to jamming signals and interference than others.
The tutorial is a technical refresher for communications engineers, field personnel, and procurement and project managers.
BIOGRAPHY
Rowan Gilmore is CEO of EM Solutions, a Brisbane-based technology developer and advanced manufacturer of high-speed microwave radio and mobile satellite communications terminals. Since joining EM Solutions in 2011, the company has quadrupled its revenues and won a number of prestigious awards, including the 2016 Brisbane Lord Mayor’s Business Award for Innovation and the 2018 Australian CASG Defence SME of the Year and Essington Lewis Awards. The company exports over half its products, which are in use by customers including the Royal Australian Navy, Spanish Army, a number of NATO Navies, and NICT of Japan. In 2019 EM Solutions was acquired by EOS, an ASX-300 company.
He was previously CEO of the Australian Institute for Commercialisation, where he helped numerous start-up companies and worked to accelerate technology transfer between research institutions and industry.
He has forty years experience in the ICT industry, and spent over a decade in the US and later in Europe, most recently as Vice President of Network Services for the airline IT company SITA, now France Telecom’s Orange subsidiary, and with Schlumberger prior to that.
Rowan is a graduate of the University of Queensland (UQ) and Washington University in St Louis, Missouri where he earned his doctorate in electrical engineering.