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Visar resultat 16 - 20 av 213 avhandlingar som matchar ovanstående sökkriterier.

1. 16. Measurement-Based Modeling of Wireless Propagation Channels - MIMO and UWB

   Författare :Johan Kåredal; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; personal area networks; MIMO; channel modeling; Propagation; channel measurements; vehicle-to-vehicle communicationa; ultra-wideband;

   Sammanfattning : Future wireless systems envision higher speeds and more reliable services but at the same time face challenges in terms of bandwidth being a limited resource. Two promising techniques that can provide an increased throughput without requiring additional bandwidth allocation are multiple-input multiple-output (MIMO) systems and ultra-wideband (UWB) systems. LÄS MER

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

   Författare :Aidin Razavi; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 18. Integrated Sensing and Communication in Cell-Free Massive MIMO

   Författare :Zinat Behdad; Cicek Cavdar; Ki Won Sung; Özlem Tugfe Demir; Huseyin Arslan; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Integrated sensing and communication; cell-free massive MIMO; power allocation; URLLC; C-RAN; convex-concave programming.; Integrerad avkänning och kommunikation; cellfri massiv MI- MO; effektallokering; URLLC; C-RAN; konvex-konkav programmering;

   Sammanfattning : Future mobile networks are anticipated to not only enhance communication performance but also facilitate new sensing-based applications. This highlights the essential role of integrated sensing and communication (ISAC) in sixth-generation (6G) and beyond mobile networks. LÄS MER

5. 19. Iterative receivers with channel estimation for MIMO and multi-user OFDM systems

   Författare :Peter Hammarberg; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Iterative receiver; channel estimation; multi-user detection; OFDM; MIMO; IDMA; complexity; EXIT chart; channel measurements.;

   Sammanfattning : The traffic in wireless networks has been showing an exponential growth over the last decade. In order to meet the demand, and support a continuation of this growth, the scarce radio resources need to be efficiently used. LÄS MER

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

   Författare :Ahmed Hussain; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER