Sökning: "large signal modulation"

Visar resultat 1 - 5 av 79 avhandlingar innehållade orden large signal modulation.

  1. 1. Modulation and channel effects in digital communication

    Författare :Sara Sandberg; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

    Sammanfattning : This thesis investigates three possible methods to increase the performance of digital communication systems, with focus on wireless systems, by accounting for some of the channel effects that may occur. The modulation scheme plays an important role in the impact of different channel effects on system performance and this work considers both a single-carrier system and orthogonal frequency-division multiplexing (OFDM). LÄS MER

  3. 2. Nonlinear Characterization of Wideband Microwave Devices and Dispersive Effects in GaN HEMTs

    Författare :Sebastian Gustafsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; large-signal; dispersive effects; electron trapping; thermal coupling; HEMT; GaN; microwave; wideband;

    Sammanfattning : Measurements play a key role in the development of microwave hardware as they allow engineers to test and verify the RF performance on a system, circuit, and component level. Since modern cellular standards employ complex modulation formats with wider signal bandwidths to cope with the growing demand of higher datarates, nonlinear characterization using wideband stimuli is becoming increasingly important. LÄS MER

  4. 3. Parameter Estimation and Waveform Fitting for Narrowband Signals

    Författare :Tomas Andersson; Peter Händel; István Kollár; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signal Processing; Signalbehandling; Signal processing; Signalbehandling;

    Sammanfattning : Frequency estimation has been studied for a large number of years. One reason for this is that the problem is easy to understand, but difficult to solve. Another reason, for sure, is the large number of applications that involve frequency estimation, e. LÄS MER

  5. 4. Vertical-Cavity Surface-Emitting Lasers: Large Signal Dynamics and Silicon Photonics Integration

    Författare :Emanuel Haglund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; vertical-cavity surface-emitting laser VCSEL .; silicon photonics; high-speed modulation; semiconductor lasers; optical interconnects; laser dynamics; large signal modulation; Heterogeneous integration;

    Sammanfattning : The GaAs-based vertical-cavity surface-emitting laser (VCSEL) is the standard light source in today's optical interconnects, due to its energy efficiency, low cost, and high speed already at low drive currents. The latest commercial VCSELs operate at data rates of up to 28 Gb/s, but it is expected that higher speeds will be required in the near future. LÄS MER

  7. 5. Modulation of Neuronal Functions : the Role of SLC10A4

    Författare :Kalicharan Patra; Klas Kullander; Håkan Aldskogius; Per Svenningsson; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; dopamine; acetylcholine; central nervous system; neuromuscular junctions; electrophysiology; monoamine; synaptic transmission; neuromodulation; Neuroscience; Neurovetenskap;

    Sammanfattning : Mental health of a person depends on the correct functioning of the brain. The brain and the spinal cord contain many types of cells, of which one important type are called the neurons. Neurons are special in the way they connect to each other to form large networks. LÄS MER