Sökning: "4G mobile communication systems"

Visar resultat 1 - 5 av 19 avhandlingar innehållade orden 4G mobile communication systems.

1. 1. Secure GNSS-based Positioning and Timing : Distance-Decreasing attacks, fault detection and exclusion, and attack detection with the help of opportunistic signals

   Författare :Kewei Zhang; Panagiotis Papadimitratos; Erik G. Larsson; Christina Pöpper; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : With trillions of devices connected in large scale systems in a wired or wireless manner, positioning and synchronization become vital. Global Navigation Satellite System (GNSS) is the first choice to provide global coverage for positioning and synchronization services. LÄS MER

3. 2. Managing Radio and Energy Resources in LTE-Based Military Training Networks

   Författare :Hawar Ramazanali; Alexey Vinel; Magnus Jonsson; Dmitry Petrov; Högskolan i Halmstad; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 4G; 5G; LTE; DRX;

   Sammanfattning : The number of wireless connected devices are growing exponentially and the importance of this research area is growing as well to meet the known and looming challenges and expectations. The 5:th Generation telecommunications standard is partly embodied by the Machine-to-Machine (M2M) and Internet of Things (IoT) technologies and standards to handle a big part of these devices and connections. LÄS MER

4. 3. 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

5. 4. Millimeter-wave Transceiver ICs for Ultrahigh Data Rate Communications Using Advanced III-V and Silicon Technologies

   Författare :Sona Carpenter; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; D-band; frequency multiplier; 110-170 GHz; QPSK; demodulator; I Q modulator; transmitter; high-order modulation; receiver; high data rate; single chip; SiGe BiCMOS; QAM; InP DHBT; direct conversion; Gilbert-cell mixer; millimeter-wave communication; 5G; MMIC; point-to-point radio.;

   Sammanfattning : Today’s main driving parameter for radio transceiver research is the ability to provide high capacity while maintaining low cost, small form factor, and low power consumption. Direct conversion architectures (due to the feasibility of monolithic integration) at millimeter-wave (due to wideband availability) have attracted large interest in recent years because of their potential to meet these demands. LÄS MER

7. 5. Characterization of Small Antennas & Wireless Devices for MIMO Systems in Rich Isotropic Multipath & Random Line-of-Sight

   Författare :Ahmed Hussain; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MIMO; Rayleigh; reverberation chamber; random LOS; RIMP; LTE; OTA;

   Sammanfattning : The current thesis is about over-the-air (OTA) performance characterization of wireless terminals in rich isotropic multipath (RIMP) environment as well as in pure line-of-sight (LOS) environment while not ignoring the random positions and orientations of the mobile terminals due to randomness of the user. The latest mobile wireless terminals such as iPhone and iPad can be used in any random position and orientation thereby making the received LOS-component toappear as a random voltage at the antenna ports. LÄS MER