MIT-Harvard CINCS (Communications Information Networks Circuits and Signals) / Hamilton Institute Seminar
Speaker: Professor Simon Cotton, Queen's University Belfast
Title: "Modelling Composite Fading in Wireless Channels"
Abstract: Understanding how the received signal can fade is essential for wireless system design. It is also critical for analysing their capacity and performance. Traditionally, the fluctuation of the received signal observed in wireless systems is decomposed into two separate components which are determined by either the distance or duration over which perturbations are observed to occur. For distance, it’s large-scale and small-scale fading, over time, its long-term and short-term fading. In wireless communications, the large-scale and long-term components are often interchangeably referred to as shadowing, while the small-scale and short-term components are simply referred to as fading. This separation is usually performed as a step of convenience in the modelling of wireless channels as it makes any ensuing statistical analysis of the signal fluctuations simpler. Nonetheless, it does have its drawbacks including the requirement to determine an appropriate smoothing window, which in turn can affect parameter estimation as well as any inferences made from the data about the wireless channel.
To this end, a number of studies have proposed the use of composite fading models, also called shadowed fading models, as they take into account the simultaneous impact of shadowing and fading. In this talk, we will briefly review a number of classical and new statistical models used to characterise shadowing (e.g. lognormal, gamma and inverse gamma) and fading (e.g. Rayleigh, Rice, Nakagami-m and κ-μ) in wireless channels. Building upon this a number of new single and double composite fading models will be introduced including the F, κ-μ / inverse gamma and double shadowed Rician. Core to the acceptance of any new composite fading model is a sound physical motivation. This aspect of the new models will also be discussed. Throughout the talk, data obtained from field measurements for emergent wireless applications including device-to-device communications, vehicle-to-vehicle communications and wearables will be used to provide example use cases for the proposed models.
Bio: Simon L. Cotton received the B.Eng. degree in electronics and software from Ulster University, Ulster, U.K., in 2004, and the Ph.D. degree in electrical and electronic engineering from the Queen’s University of Belfast, Belfast, U.K., in 2007. From 2007 to 2011 he was a Research Fellow, then Senior Research Fellow, 2011 to 2012, Lecturer (Assistant Professor), 2012 to 2015, and Reader (Associate Professor), 2015 to 2019 at the Queen’s University of Belfast. He is currently a Full Professor and the Director of the Centre for Wireless Innovation (CWI) at Queen’s University Belfast. Professor Cotton has authored and co-authored over 150 publications in major IEEE/IET journals and refereed international conferences, two book chapters, and two patents. Among his research interests are cellular device-to-device, vehicular, and body-centric communications. His other research interests include radio channel characterization and modeling, and the simulation of wireless channels. Professor Cotton was awarded the H. A. Wheeler Prize, in July 2010, by the IEEE Antennas and Propagation Society for the best applications journal paper in the IEEE Transactions on Antennas and Propagation during 2009. In July 2011, he was awarded the Sir George Macfarlane Award from the U.K. Royal Academy of Engineering in recognition of his technical and scientific attainment since graduating from his first degree in engineering.