Sökning: "Multiple antenna systems"

Visar resultat 1 - 5 av 128 avhandlingar innehållade orden Multiple antenna systems.

1. 1. Systematic Antenna Design Using the Theory of Characteristic Modes

   Författare :Zachary Miers; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Theory of Characteristic Modes; Antenna Design; Antenna; Characteristic Modes; Computational Electromagnetics; MIMO Systems; MIMO Antenna; MIMO; Mutual Coupling; Mobile Antenna;

   Sammanfattning : The day Faraday moved a magnet in and out of a wire loop and detected the time-varying magnetic field, the first wireless transmitter / receiver system was created and the world was changed forever. However, it took almost fifty years for Heinrich Hertz to use Maxwell's equations and Faraday's insights in his professorship at Karlsruhe to create the first electromagnetic wireless communication system using a spark gap dipole transmitter and a loop antenna-based receiver. LÄS MER

3. 2. Investigating and Enhancing Performance of Multiple Antenna Systems in Compact MIMO/Diversity Terminals

   Författare :Shuai Zhang; Sailing He; Raj Mittra; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple antennas; planar inverted-F antenna; mutual coupling; slot antenna; compact antenna; mobile antenna; Q factors; antenna array; ultra-wideband UWB antenna; pattern diversity; polarization diversity; user effects; adaptive arrays; chassis mode;

   Sammanfattning : Today, owners of small communicating device are interested in transmitting or receiving various multimedia data. By increasing the number of antennas at the transmitter and/or the receiver side of the wireless link, the diversity/Multiple-Input Multiple-Output (MIMO) techniques can increase wireless channel capacity without the need for additional power or spectrum in rich scattering environments. LÄS MER

4. 3. On MIMO Systems and Adaptive Arrays for Wireless Communication : Analysis and Practical Aspects

   Författare :Mattias Wennström; Michael A. Jensen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Systemteknik; antenna array; calibration; MIMO system; flat fading; non-linear amplifier; switched parasitic antenna; analog beamformer; adaptive antenna testbed; Systemteknik; Systems engineering; Systemteknik; Signal Processing; signalbehandling;

   Sammanfattning : This thesis is concerned with the use of multiple antenna elements in wireless communication over frequency non-selective radio channels. Both measurement results and theoretical analysis are presented. New transmit strategies are derived and compared to existing transmit strategies, such as beamforming and space-time block coding (STBC). LÄS MER

5. 4. Design and Performance of Diversity based Wireless Interfaces for Sensor Network Nodes

   Författare :Magnus Jobs; Anders Rydberg; Shi Cheng; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless; Sensor; Network; WSN; Antenna; WISENET; Node; Diversity; Phased Array; Conformal; WBAN; Body Area; Engineering Science with specialization in Microwave Technology; Teknisk fysik med inriktning mot mikrovågsteknik;

   Sammanfattning : The main focus of the work presented in this licentiate thesis concerns antenna design, adaptive antenna control and investigation on how the performance of small wireless nodes can be increased by inclusion of multiple antennas. In order to provide an end-user suitable solution for wireless nodes the devices require both small form factor and good performance in order to be competitive on the marked and thus the main part of this thesis focuses on techniques developed to achieve these goals. LÄS MER

7. 5. Robust Low-Cost Multiple Antenna Processing for V2V Communication

   Författare :Chouaib Bencheikh Lehocine; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Directional antennas; Beamforming; Multiple antennas; Periodic communication; Broadcast V2V communication; Hybrid combining;

   Sammanfattning : Cooperative V2V communication with frequent, periodic broadcast of messages between vehicles is a key enabler of applications that increase traffic safety and traffic efficiency on roads. Such broadcast V2V communication requires an antenna system with omnidirectional coverage, which is difficult to achieve using a single antenna element. LÄS MER