Sökning: "Ultra-wideband"

Visar resultat 16 - 20 av 60 avhandlingar innehållade ordet Ultra-wideband.

1. 16. Electron Tunneling and Field-Effect Devices in mm-Wave Circuits

   Författare :Mikael Egard; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; negative differential conductance oscillator; resonant tunneling diode; ultra-wideband; impulse radio; Wavelet generator; MOSFET; nanowire; high frequency characterization; Fysicumarkivet A:2012:Egard;

   Sammanfattning : Short high-frequency electromagnetic pulses, also referred to as wavelets, are considered for use in various short-range impulse based ultra-wideband applications, such as communication, imaging, radar, spectroscopy, and localization. This thesis investigates field-effect and tunneling based semiconductor devices and their operation in millimeter-wave (mm-wave) impulse transceivers. LÄS MER

3. 17. Accuracy and Delay: An Inherent Trade-off in Cooperative UWB Navigation

   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; positioning; Ultra-wideband; navigation; MAC delay; localization.; S-TDMA;

   Sammanfattning : Location-aware applications and wireless sensor networks are becoming essential in our daily lives from a commercial, and public perspectives. The need of localization information to drive the applications is a key requirement. New technologies have emerged to tackle the problem of the limitations of the Global Positioning System (GPS) solutions. LÄS MER

4. 18. 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

5. 19. Impulse Radio UWB for the Internet-of-Things : A Study on UHF/UWB Hybrid Solution

   Författare :Zhuo Zou; Hannu Tenhunen; Tor Sverre Lande; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ultra-Wideband; impulse radio; IR-UWB; RFID; asymmetric links; UHF UWB hybrid; wireless sensing; energy detection; low power; radio receiver; positioning; Internet-of-Things;

   Sammanfattning : This dissertation investigates Ultra-Wideband (UWB) techniques for the next generation Radio Frequency Identification (RFID) towards the Internet-of-Things (IoT). In particular, an ultra-high frequency (UHF) wireless-powered UWB radio (UHF/UWB hybrid) with asymmetric links is explored from system architecture to circuit implementation. LÄS MER

7. 20. 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