Sökning: "Channel noise"

Visar resultat 1 - 5 av 271 avhandlingar innehållade orden Channel noise.

1. 1. Development and Application of Reactor Noise Diagnostics

   Författare :Joakim K.-H. Karlsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; BWR stability; noise decomposition; reactor noise; control rod vibrations; core barrel vibration; density wave oscillations; noise diagnostics; PWR noise; localisation; channel instability;

   Sammanfattning : A number of problems in reactor noise diagnostics have been investigated within the framework of the present thesis. The six papers presented cover three relatively different areas, namely the use of analytical calculations of the neutron noise in simple reactor models, some aspects of boiling water reactor (BWR) stability and diagnostics of core barrel motion in pressurized water reactors (PWRs). LÄS MER

3. 2. Design and Fabrication of InP High Electron Mobility Transistors for Cryogenic Low-Noise Amplifiers

   Författare :Junjie Li; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Channel noise; InP HEMT; cryogenic; subthreshold swing.; noise temperature; spacer thickness; low-noise amplifier;

   Sammanfattning : High electron mobility transistor (InP HEMT) cryogenic low noise amplifiers (LNAs) have made significant improvements in noise and gain following decades of development. Applications are found from radio astronomy to quantum computing. LÄS MER

4. 3. 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

5. 4. GaN HEMT Low Frequency Noise Characterization for Low Phase Noise Oscillator Design

   Författare :Thi Ngoc Do Thanh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low frequency noise; flicker noise; phase noise; deposition method.; oscillator; VCO; GaAs pHEMT; MMIC; GaN HEMT; passivation; InGaP HBT;

   Sammanfattning : The thesis presents low frequency noise (LFN) characterization of Gallium Nitride (GaN) High Electron Mobility Transistors (HEMTs) for low phase noise oscillator design. First, GaN HEMT technology is benchmarked versus other transistor technologies, e.g. LÄS MER

7. 5. Phase Noise in Communication Systems--Modeling, Compensation, and Performance Analysis

   Författare :M Reza Khanzadi; Chalmers tekniska högskola; []
   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; multiple antennas; distributed oscillators.; colored phase noise; free-running oscillator; Bayesian Cramér-Rao bound; Oscillator phase noise; phase noise model; channel capacity; mean square error; capacity achieving distribution; Wiener process; extended Kalman filter smoother; maximum a posteriori estimator; phase-locked loop;

   Sammanfattning : The continuous increase in demand for higher data rates due to applications with massive number of users motivates the design of faster and more spectrum efficient communication systems. In theory, the current communication systems must be able to operate close to Shannon capacity bounds. LÄS MER