Sökning: "free-running oscillator"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden free-running oscillator.

  1. 1. Low Noise Oscillator in ADPLL toward Direct-to-RF All-digital Polar Transmitter

    Författare :Jian Chen; Li-Rong Zheng; Fredrik Jonsson; Hannu Tenhunen; Georges Gielen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; all-digital; digitally-intensive; frequency modualtion; phase modulation; amplitude modulation; polar; transmitter; oscillator; digital controled oscillator; DCO; VCO; voltage controled oscillator; class-C oscillator; class-D PA; ADPLL; phase noise; RF; CMOS.;

    Sammanfattning : In recent years all-digital or digitally-intensive RF transmitters (TX) have attracted great attention in both literature and industry. The motivation is to implement RF circuits in a manner suiting advanced nanometer CMOS processes. To achieve that, information is encoded in the time-domain rather than voltage amplitude. LÄS MER

  3. 2. 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

  4. 3. Modeling and Estimation of Phase Noise in Oscillators with Colored Noise Sources

    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; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Phase Noise Model; Bayesian Cramer-Rao Bound; Voltage-controlled Oscillator; Extended Kalman Filter Smoother; Maximum a Posteriori Estimator; Colored Phase Noise; Oscillator Phase Noise; Phase-Locked Loop; Mean Square Error.;

    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

  5. 4. Spectral Management in Quasi-Phase-Matched Parametric Devices

    Författare :Mikael Tiihonen; Fredrik Laurell; Jean-Jaques Zondy; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; optical parametric devices; nonlinear optics; ultraviolet generation; mid-infrared generation; optical parametric oscillator; optical parametric generator; optical parametric amplifier; Optical physics; Optisk fysik;

    Sammanfattning : Nonlinear optical interaction in quasi-phase-matched structures opens up unique possibilities to build compact and efficient parametric devices such as optical parametric oscillators, generators, and amplifiers with tailored spectral properties. The focus of this thesis is on novel parametric interactions with periodically-poled KTiOPO4 (PPKTP) as the parametric gain medium. LÄS MER

  7. 5. Self-Homodyne Coherent Systems using Advanced Modulation Formats

    Författare :Martin E Sjödin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Modulation formats that offer high spectral efficiency will be of great importance in future fiber optic communication systems. Currently, a lot of research effortsare ongoing to investigate the best ways of generating and detecting modulation formats in which both the phase and the amplitude of the light are used to carry information, such as 16-QAM. LÄS MER