KUKU

KU ScholarWorks

  • myKU
  • Email
  • Enroll & Pay
  • KU Directory
    • Login
    View Item 
    •   KU ScholarWorks
    • Dissertations and Theses
    • Theses
    • View Item
    •   KU ScholarWorks
    • Dissertations and Theses
    • Theses
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Sidelobe suppression for OFDM based cognitive radios in dynamic spectrum access networks

    Thumbnail
    View/Open
    Pagadarai_Srikanth_2007_6599252.pdf (1.310Mb)
    Issue Date
    2007-08-31
    Author
    Pagadarai, Srikanth
    Publisher
    University of Kansas
    Type
    Thesis
    Degree Level
    M.S.
    Discipline
    Electrical Engineering & Computer Science
    Rights
    This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
    Metadata
    Show full item record
    Abstract
    As the demand for sophisticated wireless mobile applications incorporating efficient modulation techniques is ever increasing, more bandwidth is needed to support these applications. However, bandwidth is a limited resource. Also, as the existing spectrum allocation policies of the Federal Communications Commission (FCC) allow spectrum access to licensed users only, it has been proven by various spectrum measurement campaigns that, the current licensed spectrum usage across time and frequency is inefficient. Therefore, in order for the unlicensed users to access the unused portions of the licensed spectrum, the concept of "spectrum pooling" has been proposed.

    Spectrum pooling is based on dynamic spectrum access (DSA), wherein the secondary user decides on whether or not a particular frequency band is currently being used and transmits the signal in that unused licensed band, while ensuring that the system performance of the primary as well as the secondary is not impacted. Thus, coexistence of the primary and the secondary users is an important criterion that makes DSA a feasible solution for efficient spectrum usage. This thesis investigates an important problem concerning the coexistence of the primary and the secondary users.

    Orthogonal frequency division multiplexing (OFDM) has proven to be the prime candidate for spectrum pooling based wireless transmission systems as it can support high data rates and is robust to channel impairments. Even though the secondary transmissions help in improving the spectral efficiency by transmitting in the spectral white spaces left unused by the primary users, the large sidelobes resulting from the use of OFDM result in high out-of-band (OOB) radiation. Thus, the coexistence of the primary and the secondary users in the form of spectrum sharing is dependant on the suppression of the interference from the rental systems to the legacy systems. This thesis presents two novel techniques to suppress the OOB interference from the secondary user to the primary user, while not affecting the other system parameters of the secondary user by a great deal.
    Description
    Thesis (M.S.)--University of Kansas, Electrical Engineering & Computer Science, 2007.
    URI
    http://hdl.handle.net/1808/32081
    Collections
    • Theses [3828]

    Items in KU ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.


    We want to hear from you! Please share your stories about how Open Access to this item benefits YOU.


    Contact KU ScholarWorks
    785-864-8983
    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    785-864-8983

    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    Image Credits
     

     

    Browse

    All of KU ScholarWorksCommunities & CollectionsThis Collection

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Contact KU ScholarWorks
    785-864-8983
    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    785-864-8983

    KU Libraries
    1425 Jayhawk Blvd
    Lawrence, KS 66045
    Image Credits
     

     

    The University of Kansas
      Contact KU ScholarWorks
    Lawrence, KS | Maps
     
    • Academics
    • Admission
    • Alumni
    • Athletics
    • Campuses
    • Giving
    • Jobs

    The University of Kansas prohibits discrimination on the basis of race, color, ethnicity, religion, sex, national origin, age, ancestry, disability, status as a veteran, sexual orientation, marital status, parental status, gender identity, gender expression and genetic information in the University’s programs and activities. The following person has been designated to handle inquiries regarding the non-discrimination policies: Director of the Office of Institutional Opportunity and Access, IOA@ku.edu, 1246 W. Campus Road, Room 153A, Lawrence, KS, 66045, (785)864-6414, 711 TTY.

     Contact KU
    Lawrence, KS | Maps