Search for dissertations about: "Pulse Density Modulation"

Showing result 1 - 5 of 11 swedish dissertations containing the words Pulse Density Modulation.

2. 1. Quantization and Noise-Shaped Coding for High Efficiency Transmitter Architectures

   Author : Ulf Gustavsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Software Defined Radio; Quantization; damped Gauss-Newton; Pulse Density Modulation; Noise-Shaped Coding; ΣΔ-Modulators; Power Amplifier;

   Abstract : Three driving parameters in the development of transmitter technologies for wireless communication today is: energy efficiency, flexibility and footprint reduction. This thesis investigates the use of 1-bit oversampled signal representation, mainly as a power efficiency enhancement technique for the transmitter, but also as a path toward reduced footprint and increased flexibility. READ MORE

4. 2. Acoustical Measurements of Material Nonlinearity and Nonequilibrium Recovery

   Author : Kristian Haller; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear acoustics; nondestructive testing; activation density; slow dynamics; nonequilibrium recovery; resonance frequency; nonlinear wave modulation spectroscopy; harmonic generation; trapped modes; open resonator; sweep rate; constant strain sweep;

   Abstract : A damaged material or a material with non perfect atomic geometry, dislocations or cracks, exhibits two types of characteristic responses to acoustic excitations. First is the fast nonlinear dynamics response that is present as long as the material is excited. As soon as the excitation stops the response disappear. READ MORE

5. 3. Bit-Wise Decoders for Coded Modulation and Broadcast Coded Slotted ALOHA

   Author : Mikhail Ivanov; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mutual information; vehicular communications; bit-interleaved coded modulation; error floor; slotted ALOHA; medium access control; All-to-all broadcast;

   Abstract : This thesis deals with two aspects of wireless communications. The first aspect is about efficient point-to-point data transmission. To achieve high spectral efficiency, coded modulation, which is a concatenation of higher order modulation with error correction coding, is used. READ MORE

6. 4. Inverter Design for SiC-based Electric Drive Systems with Optimal Redundant States Control of Space Vector Modulation

   Author : Georgios Mademlis; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Vehicle; Common Mode Voltage; Power Hardware-in-the-Loop; Tidal power; Voltage balancing; Silicon Carbide SiC ; Medium Voltage Converters; Multilevel; Neutral Point Clamped NPC ; Maximum Power Point Tracking MPPT ; Space Vector Modulation;

   Abstract : The need for inverters with ever increasing power density and efficiency has recently become the driving factor for research in various fields. Increasing the operating voltage of the whole drive system and utilizing newly developed SiC power switches can contribute towards this goal. READ MORE

7. 5. From Noise-Shaped Coding to Energy Efficiency - One bit at the time

   Author : Ulf Gustavsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; radio frequency power amplifier; power efficiency; ΣΔ-modulation;

   Abstract : Three parameters that drive the research and development of future RF transmitter technologies for high speed wireless communication today are energy efficiency, flexibility and reduction of the physical footprint. This thesis treats the use of single-bit quantization in conjunction with a method called Noise-Shaped Coding (NSC), as an enabler for these parameters, foremost in terms of energy efficiency. READ MORE