Sökning: "Spectrum Utilization"

Visar resultat 1 - 5 av 64 avhandlingar innehållade orden Spectrum Utilization.

  1. 1. Efficient Spectrum Utilization of Uhf Broadcast Band

    Författare :Lei Shi; Jens Zander; Ki Won Sung; Linda Dolye; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TV White Space; CellTV; UHF Band; Spectrum; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The UHF band between 470-790 MHz, currently occupied by digital ter- restrial TV (DTT) distribution in Europe, is widely regarded as a premium spectrum band for providing mobile coverage. With the exponential increase in wireless data traffic in recent years, there has been growing interests in gaining access to this spectrum band for wireless broadband services. LÄS MER

  3. 2. Topics in Dynamic Spectrum Access : Market Based Spectrum Sharing and Secondary User Access in Radar Bands

    Författare :Miurel Tercero Vargas; Jens Zander; Mikael Prytz; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; spectrum sharing; radar band; cognitive radio; Telecommunication; Telekommunikation; Systems engineering; Systemteknik;

    Sammanfattning : The steady growth in demand for spectrum has increased research interest in dynamic spectrum access schemes. This thesis studies some challenges in dynamic spectrum access based on two strategies: open sharing and hierarchical access. LÄS MER

  4. 3. Cognitive Sensing and Transmission Strategies

    Författare :Kasra Haghighi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hidden Markov Model; Spectrum Sensing; Sequential Spectrum Sensing; Cognitive Radio; Spectrum Utilization;

    Sammanfattning : Many frequency bands for wireless services are severely underutilized by the primary users (PU) to which these bands are assigned. This motivates cognitive radios (CR), which identifies vacant spectrum and transmit accordingly. Many algorithms, some as simple as energy detection, are used to sense the spectrum. LÄS MER

  5. 4. Spectrum Sensing for Dynamic Spectrum Access in Cognitive Radio

    Författare :Inna Valieva; Dag Stranneby; Mälardalens universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Abstract. The number of mobile devices is constantly growing, and the exclusivestatic spectrum allocation approach is leading to the spectrum scarcity problem whensome of the licensed bands are heavily occupied and others are nearly unused.Spectrum sharing and opportunistic spectrum access allow achieving more efficientspectrum utilization. LÄS MER

  7. 5. Spectrum Sensing for Cognitive Radio

    Författare :Inna Valieva; Krister Landernäs; Mälardalens universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; elektronik; Electronics;

    Sammanfattning : This work focuses on the improvement of spectrum utilization by evaluating and proposing a subset of radio scene analysis algorithms for opportunistic spectrum access deployment in a cognitive radio network. The proposed algorithms aim to solve two problems: detecting vacant frequency channels and estimating the waveform, including modulation type, symbol rate, and central frequency. LÄS MER