از سری سمینارهای ادواری گروه علوم مهندسی فرهنگستان علوم، شاخه مهندسی برق و کامپیوتر، سمینار افق‌های آینده مهندسی برق و کامپیوتر با موضوع «فناوری سطوح هوشمند و کاربردهای متعدد آن در مخابرات بی سیم» توسط پروفسور Emil Björnson استاد حوزه مخابرات بیسیم در اینستیتو تکنولوژی سلطنتی KTH در استکلهم سوئد در تاریخ دوشنبه ۷ خرداد ۱۴۰۳ ساعت ۱۳:۳۰ تا ۱۵ برگزار می شود.
لینک اتاق مجازی: https://www.skyroom.online/ch/ias/engineering
Abstract:
Wireless systems have traditionally been designed to operate under the channel conditions provided by nature. The advent of reconfigurable intelligent surfaces (RIS) changes the status quo by adding the ability to control wave propagation. A RIS is an array of reflecting elements with properties that can be tuned in real-time to synthesize the reflection behavior of a differently shaped object. This feature is helpful for both communications and localization. There are many ways that a RIS can improve the wireless channel between a transmitter and a receiver. The larger the surface is, the higher the potential communication performance improvement. The gains are achieved by adapting the RIS configuration to the channel coefficients from the transmitter to the receiver via the RIS, which must be estimated in practice. The estimation challenge grows with the number of reflecting elements, in terms of computational complexity and signal resources required for pilot signaling. The problem differs greatly from the classical estimation problems in multi-antenna communications because the RIS is blind and substantially larger. Hence, there is a substantial risk that the estimation dimensionality will be the showstopper in practice. In this talk, we will look at how classical signal processing theory provides suitable tools to describe and analyze RIS systems. We will first explore how these tools enable us to model the physical channels that interact with a RIS. We will then simplify the channel estimation problem by exploiting the fundamental channel properties, such as the array geometry, array responses, and channel geometry. It turns out that, under the right circumstances, array processing methodology is the key to making RIS a practically viable technology.
Biography:
Emil Björnson is a Professor of Wireless Communication at the KTH Royal Institute of Technology, Stockholm, Sweden. He is an IEEE Fellow, Digital Futures Fellow, and Wallenberg Academy Fellow. He has a podcast and YouTube channel called Wireless Future. His research focuses on multi-antenna communications and radio resource management, using methods from communication theory, signal processing, and machine has authored four textbooks and published a large amount of simulation code. learning. He He has received the 2018 and 2022 IEEE Marconi Prize Paper Awards in Wireless Communications, the 2019 EURASIP Early Career Award, the 2019 IEEE Communications Society Fred W. Ellersick Prize, the 2019 IEEE Signal Processing Magazine Best Column Award, the 2020 Pierre-Simon Laplace Early Career Technical Achievement Award, the 2020 CTTC Early Achievement Award, the 2021 IEEE ComSoc RCC Early Achievement Award, and the 2023 IEEE Communications Society Outstanding Paper Award. His work has also received six Best Paper Awards at conferences.
