Sökning: "Antenna limitation"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Antenna limitation.

1. 1. Antenna Limitations and Q-factor Trade-off between Parameters, Steps towards Optimal Antenna Design

   Författare :Shuai Shi; Lars Jonsson; Ala Sharaiha; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Antenna limitation; Q-factor; directivity; radiation pattern; current optimization; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Sub-wavelength antennas have become ubiquitous in essential devices, such as mobile phones, sensors, Internet of things (IoT) and machine to machine (M2M) communication devices. Such antennas are often embedded as a small part of the device chassis or their circuit-boards. LÄS MER

3. 2. High Capacity Fiber-Connected Wireless MIMO Communication

   Författare :Husileng Bao; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; central unit; Radio-over-Fiber; millimeter-wave.; multiple-inputmultiple- output; remote radio head;

   Sammanfattning : There will be more and more users while beyond-5G (B5G) and 6G bring more wireless applications. Current cellular communication networks assign specific serving boundaries for each radio, which becomes a limitation when too many users work with one radio simultaneously. By physically distributing radios. user’s service can be more uniform. LÄS MER

4. 3. Multiantenna Wireless Architectures with Low Precision Converters

   Författare :Yasaman Ettefagh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; massive MIMO; fronthaul link; normal approximation; random coding union bound with parameter s; data converters; outage probability;

   Sammanfattning : One of the main key technology enablers of the next generation of wireless communications is massive multiple input multiple output (MIMO), in which the number of antennas at the base station (BS) is scaled up to the order of tens or hundreds. It provides considerable energy and spectral efficiency by spatial multiplexing, which enables serving multiple user equipments (UEs) on the same time and frequency resource. LÄS MER

5. 4. Integrated millimeter Wave CMOS Power Amplifiers for 5G Systems

   Författare :Christian Elgaard; Integrerade elektroniksystem; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The anticipated continuation of the last three decades of growth of global demand for high-speed high-coverage mobile data, calls for massive investments in cellular infrastructure, for the ongoing roll out of the fifth generation of mobile systems, but also later for the sixth generation. A key enabler, for the high-speed part, is for the cellular system to move up in frequency and support communication at millimeter-wave (mmW) frequencies (24 – 70 GHz), where available wideband spectrum exist. LÄS MER

7. 5. Channel Estimation and Prediction for 5G Applications

   Författare :Rikke Apelfröjd; Mikael Sternad; Emil Björnson; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Channel estimation; Channel prediction; Channel smoothing; Linear estimation; Kalman filter; Massive MIMO; Coordinated Multipoint transmission; Robust precoding; Predictor antennas; Limits of predictability; Long range predictions; Electrical Engineering with specialization in Signal Processing; Elektroteknik med inriktning mot signalbehandling;

   Sammanfattning : Accurate channel state information (CSI) is important for many candidate techniques of future wireless communication systems. However, acquiring CSI can sometimes be difficult, especially if the user equipment is mobile in which case the future channel realisations must be estimated/predicted. LÄS MER