Sökning: "Reconfigurable surfaces"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden Reconfigurable surfaces.

  1. 1. Channel Estimation Aspects of Reconfigurable Intelligent Surfaces

    Författare :Doga Gürgünoglu; Gabor Fodor; Emil Björnson; Jaap van de Beek; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reconfigurable intelligent surface; channel estimation; pilot contamination; positioning; angle of arrival estimation; integrated sensing and communications; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In the sixth generation of wireless communication systems (6G), there exist multiple candidate enabling technologies that help the wireless network satisfy the ever-increasing demand for speed, coverage, reliability, and mobility. Among these technologies, reconfigurable intelligent surfaces (RISs) extend the coverage of a wireless network into dead zones, increase capacity, and facilitate integrated sensing and communications tasks by consuming very low power, thus contributing to energy efficiency as well. LÄS MER

  3. 2. Selected Topics on Reconfigurable Intelligent Surfaces

    Författare :Emad Farouk Ibrahim; Rickard Nilsson; Jaap van de Beek; Laura Cottatellucci; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

    Sammanfattning : Reconfigurable intelligent surface (RIS) is a promising technology for wireless communications applications. A RIS is a thin planar array that consists of multiple reflecting elements, each of which is connected to a tunable chip and can induce a controllable reflection coefficient to the incident signal. LÄS MER

  4. 3. RF Energy Harvesting for Zero-Energy Devices and Reconfigurable Intelligent Surfaces

    Författare :Morteza Tavana; Emil Björnson; Jens Zander; George Alexandropoulos; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronic waste; energy harvesting; Internet of Things; optimization; phased array; reconfigurable intelligent surfaces; stochastic geometry; wireless power transfer; wireless sensor networks; zero-energy devices.; Elektronikskrot; energiutvinning; sakernas internet; optimering; fasstyrda antenner; omkonfigurerbara intelligenta ytor; stokastisk geometri; trådlös kraftöverföring; trådlösa sensornätverk; nollenergienheter.; Informations- och kommunikationsteknik; Information and Communication Technology;

    Sammanfattning : The growth of Internet of Things (IoT) networks has made battery replacement in IoT devices increasingly challenging. This issue is particularly pronounced in scenarios with a large number of IoT devices, in locations where IoT devices are difficult to access, or when frequent replacement is necessary. LÄS MER

  5. 4. Optimizing Energy Efficiency in Wireless Links Through Reconfigurable Intelligent Surfaces and Optimal Ratios

    Författare :Anders Enqvist; Emil Björnson; Ozlem Tugfe Demir; Cicek Cavdar; Yuanwei Liu; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 6G; Energy Efficiency; Reconfigurable Intelligent Surfaces; 6G; energieffektivitet; rekonfigurerbara intelligenta ytor; Informations- och kommunikationsteknik; Information and Communication Technology;

    Sammanfattning : This thesis explores the optimization of energy efficiency (EE) in the radiolink of wireless communication systems, focusing on both the user equipment (UE) and the base station (BS). The first part of the study examines strategies to minimize the energy consumption of the UE when transmitting short data payloads, utilizing a reconfigurable intelligent surface (RIS) controlled by the BS, to improve the channel conditions. LÄS MER

  7. 5. Beyond Massive MIMO : Trade-offs and Opportunities with Large Multi-Antenna Systems

    Författare :Juan Vidal Alegría; Kommunikationsteknologi; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MIMO; massive MIMO; cell-free massive MIMO; Decentralized multi-antenna architectures; Decentralized schemes; WAX decomposition; LIS; Reconfigurable surfaces; RIS; IRS; ARIS; FRIS;

    Sammanfattning : After the commercial emergence of 5G, the research community is already putting its focus on proposing innovative solutions to enable the upcoming 6G. One important lesson put forth by 5G research was that scaling up the conventional multiple-input-multiple-output (MIMO) technology by increasing the number of antennas could be extremely beneficial for effectively multiplexing data streams in the spatial domain. LÄS MER