Sökning: "signal scattering"

Visar resultat 11 - 15 av 154 avhandlingar innehållade orden signal scattering.

1. 11. On the trade-off between uncertainty and delay in UWB and 5G localization

   Författare :Gabriel Garcia; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ultra-wideband; MIMO; positioning; MAC delay; localization; 5G; initial access; millimeter-wave; multipleinput multiple output;

   Sammanfattning : Location-aware technologies in combination with emerging wireless communication systems have revolutionized many aspects of our daily lives by means of applications within the commercial, public and military sectors. Ultra-wideband (UWB) and 5G stand out as emerging radio frequency (RF) based technologies that tackle the limitations of Global Positioning System solutions. LÄS MER

3. 12. Predictor Antenna Systems: Exploiting Channel State Information for Vehicle Communications

   Författare :Hao Guo; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 6G; Beyond 5G; temporal correlation; spatial correlation; wireless backhaul; outage probability; hybrid automatic repeat request HARQ ; channel state information CSI ; throughput; integrated access and backhaul IAB ; mobile relay; predictor antenna PA ; mobility; Marcum Q-function; relay; rate adaptation;

   Sammanfattning : Vehicle communication is one of the most important use cases in the fifth generation of wireless networks (5G).  The growing demand for quality of service (QoS) characterized by performance metrics, such as spectrum efficiency, peak data rate, and outage probability, is mainly limited by inaccurate prediction/estimation of channel state information (CSI) of the rapidly changing environment around moving vehicles. LÄS MER

4. 13. Microwave Measurement Systems for Parameter Estimation and Classification

   Författare :JOHAN WINGES; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microcrystalline cellulose; parameter estimation; sensitivities; microwave measurements; finite element method; gradient-based optimization; permittivity;

   Sammanfattning : Microwave measurement systems are attractive for diagnostics and monitoring purposes in a number of important applications. For example, the strong interaction between microwaves and water make microwaves well-suited for moisture measurements. LÄS MER

5. 14. Performance Analysis of Massive MIMO in Non-Ideal Settings

   Författare :Nikolaos Kolomvakis; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; massive MIMO; sparse channels; Achievable rate; IQ imbalance;

   Sammanfattning : Recent years have witnessed an unprecedented explosion in mobile data traffic, due to the expansion of numerous types of wireless devices, which have enabled a plethora of data-hungry applications. Novel techniques, such as massive multiple-input multiple-output (MIMO) systems, represent potential candidates to support these formidable demands. LÄS MER

7. 15. Theoretical Studies of Raman Scattering

   Författare :Abdelsalam Mohammed; Hans Ågren; Luciano Frediani; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; Teoretisk kemi;

   Sammanfattning : Different theoretical approaches have been presented in this thesis to study the Raman scattering effect. The first one is response theory applied up to third order of polarization, where the determination of α, β and γ is used to calculate linear Raman scattering (resonance Raman scattering (RRS) and normal Raman scattering (NRS)), hyper Raman scattering (HRS) and coherent anti-Stokes Raman scattering (CARS), respectively. LÄS MER