Search for dissertations about: "MIMO efficiency"

Showing result 11 - 15 of 81 swedish dissertations containing the words MIMO efficiency.

2. 11. Optimizing Massive MIMO : Precoder Design and Power Allocation

   Author : Hei Victor Cheng; Erik G. Larsson; Marius Pesavento; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : The past decades have seen a rapid growth of mobile data traffic,both in terms of connected devices and data rate. To satisfy the evergrowing data traffic demand in wireless communication systems, thecurrent cellular systems have to be redesigned to increase both spectralefficiency and energy efficiency. READ MORE

4. 12. Adaptation in multiple input multiple output systems with channel state information at transmitter

   Author : Jinliang Huang; Svante Signell; Anders Ahlén; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MIMO; adaptive modulation; power allocation; spectral efficiency; CSI; Electrical engineering; Elektroteknik;

   Abstract : This thesis comprises two parts: the first part presents channel-adaptive techniques to achieve high spectral efficiency in a single user multiple-input multiple-output (MIMO) system; the second part exhibits a programmable and reconfigurable software-defined-radio orkbench(SDR-WB) in the Matlab/Octave environment that accommodates a variety of wireless applications. In an attempt to achieve high spectral efficiency, an adaptive modulation technique is applied at the transmitter to vary the data rate depending on the channel state information (CSI). READ MORE

5. 13. Mobile Antenna Systems for 4G and 5G Applications with User Body Interaction

   Author : Kun Zhao; Sailing He; Cyril Luxey; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Antenna; MIMO; mmWave; Mobile communication; SAR; Power density; User body effect; Channel modeling; Multiplex efficiency; Electrical Engineering; Elektro- och systemteknik;

   Abstract : In the thesis, the user body effect on antennas in a mobile terminal is discussed. In order to overcome the degradation of Multiple-Input Multiple-Output (MIMO) performance due to the user body effect, a quad-elements MIMO antenna array which can mitigate the body effect through an adaptive antenna switching method is introduced for 4G mobile terminals. READ MORE

6. 14. Characterization and Design Requirements for Antennas in the Near-field and the Random-LOS Propagation Environment

   Author : Aidin Razavi; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polarization-MIMO; Random-LOS; OTA; Antenna measurements; near-field antennas; antenna characterization; MIMO; near-field focusing;

   Abstract : The choice of antenna for a particular application depends on the requirements imposed by that application. These can be, the application's field region (i.e., near-field or far-field), polarization, radiation pattern, radiation efficiency, system throughput, etc. READ MORE

7. 15. Characterization of Small Antennas & Wireless Devices for MIMO Systems in Multipath & Line-of-Sight

   Author : Ahmed Hussain; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; USRP; OTA; SDR; RIMP; TRP; TIS; Reverberation chamber; Rayleigh; MIMO; LOS; LTE; Throughput;

   Abstract : The current thesis investigates over-the-air (OTA) performance characterization of small antennas and wireless terminals in rich isotropic multipath (RIMP) environment, as well as in pure line-of-sight (LOS) environment when taking into account the random positions and orientations of the mobile terminals caused by the realistic user behavior. The latest mobile wireless terminals such as smart phones and tablets can be used in any random orientation thereby making even a received LOS-component appear as a random voltage at the antenna ports over time. READ MORE