Sökning: "Beamforming"

Visar resultat 16 - 20 av 99 avhandlingar innehållade ordet Beamforming.

  1. 16. 60 GHz Wireless Propagation Channels: Characterization, Modeling and Evaluation

    Författare :Carl Gustafson; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 60 GHz; mm-wave; IEEE 802.11ad; IEEE802.15.3c; Channel measurements; Channel modeling; propagation; MIMO; Beamforming; Spatial Multiplexing;

    Sammanfattning : To be able to connect wirelessly to the internet is nowadays a part of everyday life and the number of wireless devices accessing wireless networks worldwide are increasing rapidly. However, with the increasing number of wireless devices and applications and the amount available bandwidth, spectrum shortage is an issue. LÄS MER

  3. 17. Signal Processing Techniques in Mobile Communication Systems : Signal Separation, Channel Estimation and Equalization

    Författare :Ronnie Landqvist; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wireless mobile communications; signal processing; blind source separation; independent component analysis; beamforming; water filling; greedy algorithm; exact eigendecomposition; eigenvector algorithm; multiple-input multiple-output systems; the projection approximation subspace tracking algorithm with and without deflation; linear and non-linear principal component analysis; whitening; decorrelation; equalization; antenna arrays;

    Sammanfattning : Over the last decade there has been an explosive growth in the use of wireless mobile communications. Second generations systems are mature technologies now and third generation systems and beyond are being implemented and researched. LÄS MER

  4. 18. Base Station Coordination in Multicell MIMO Networks

    Författare :Nima Seifi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; beamforming; Antenna tilt; intercell interference; base station coordination; scheduling.;

    Sammanfattning : The use of multi-antenna technology, also referred to as multiple-input multipleoutput (MIMO), has been shown to improve both the achievable data rates and the link reliability in single-cell wireless systems without a need for extra power or bandwidth. The promised gains of MIMO techniques are, however, severely degraded in a multicell environment due to the presence of intercell interference,especially for users at the cell edge. LÄS MER

  5. 19. Robust Low-Cost Multiple Antenna Processing for V2V Communication

    Författare :Chouaib Bencheikh Lehocine; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Directional antennas; Beamforming; Multiple antennas; Periodic communication; Broadcast V2V communication; Hybrid combining;

    Sammanfattning : Cooperative V2V communication with frequent, periodic broadcast of messages between vehicles is a key enabler of applications that increase traffic safety and traffic efficiency on roads. Such broadcast V2V communication requires an antenna system with omnidirectional coverage, which is difficult to achieve using a single antenna element. LÄS MER

  7. 20. Transceiver Design for Multiple Antenna Communication Systems with Imperfect Channel State Information

    Författare :Xi Zhang; Björn Ottersten; Miguel Lagunas; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MIMO; imperfect CSI; linear transceiver; beamforming; user selection; robust design; channel statistics; Telecommunication; Telekommunikation;

    Sammanfattning : Wireless communication links with multiple antennas at both the transmitter and the receiver sides, so-called multiple-input-multiple-output (MIMO)systems, are attracting much interest since they can significantly increase the capacity of band-limited wireless channels to meet the requirements of the future high data rate wireless communications. The treatment of channel state information (CSI) is critical in the design of MIMO systems. LÄS MER