Sökning: "spectrum efficiency"

Visar resultat 1 - 5 av 215 avhandlingar innehållade orden spectrum efficiency.

  1. 1. On Finding Spectrum Opportunities in Cognitive Radios : Spectrum Sensing and Geo-locations Database

    Författare :Mohamed Hamid; Ben Slimane; Niclas Björsell; Muhammad Imadua Rahman; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; COgnitive Radio; Dynamic Spectrum Access; Spectrum Opportunity; Spectrum Sensing; GEo-locations database;

    Sammanfattning : The spectacular growth in wireless services imposes scarcity in term of the available radio spectrum. A solution to overcome this scarcity is to adopt what so called cognitive radio based on dynamic spectrum access. LÄS MER

  3. 2. Spectrally Efficient Continuous Phase Modulation

    Författare :Tommy Svensson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spectrum efficiency; Laurent decomposition; additive white Gaussian noise AWGN ; trellis coded modulation TCM ; non-linear channels; continuous phase modulation CPM ; maximum likelihood sequence detection MLSD ; distance spectrum; convolutional codes;

    Sammanfattning : Spectrally efficient continuous phase modulation (CPM) systems and generalizations of CPM for wireless links are considered. Continuous phase modulation defines constant envelope phase codes, which are advantageous when using non-linear amplifiers. LÄS MER

  4. 3. Removal processes in sewage treatment plants : Sludge quality and treatment efficiency of structurally diverse organic compounds

    Författare :Ulrika Olofsson; Peter Haglund; Staffan Lundstedt; Juliane Hollender; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Environmetrics; flame retardants; GCxGC; non-targeted screening; mass flow; metals; plasticizers; poorly removed contaminants; POP; PPCP; prediction; Principal Component Analysis; removal efficiency; sewage; sewage treatment plants; sludge; sludge adsorption; sources; time-trend analysis; Environmental chemistry; Miljökemi;

    Sammanfattning : Large and ever-increasing numbers of chemicals, including large quantities of a broad spectrum of organic compounds are used in modern society. More than 30 000 of the more than 100 000 chemical substances registered in the EU are estimated to be daily used, of which many will be discharged into the waste-streams handled by municipal sewage treatment plants (STPs). LÄS MER

  5. 4. Investigation of a Multilevel Inverter for Electric Vehicle Applications

    Författare :Oskar Josefsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Plug-in Electric Vehicle PEV ; Electric Vehicle EV ; LiFePO4.; Integrated Charger; Efficiency; Drive Cycle; Battery modelling; Multilevel Inverter MLI ; Two-level Inverter TLI ;

    Sammanfattning : Electrified vehicles on the market today all use the classical two-level inverter as the propulsion inverter. This thesis analyse the potential of using a cascaded H-bridge multilevel inverter as the propulsion inverter. LÄS MER

  7. 5. Integrated Transmitters for Cellular User Equipment–Wideband CMOS Power Amplifiers and Antenna Impedance Tuners

    Författare :Jonas Lindstrand; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CMOS; LTE; Impedance tuner; Injection lock; Power amplifier; Efficiency; Polar bandwidth expansion; multiband;

    Sammanfattning : The digital cellular systems era started about thirty years ago with the release of the first digital cellphones. These first digital cellphones were very different from today’s slim and esthetic cellular pocket computers. They were not mass-produced in million units a day, and they were designed for radio performance rather than appearance. LÄS MER