Sökning: "Multiple antennas"

Visar resultat 36 - 40 av 150 avhandlingar innehållade orden Multiple antennas.

  1. 36. 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

  3. 37. 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. 38. On the Impact of Phase Noise in Communication Systems –- Performance Analysis and Algorithms

    Författare :Rajet Krishnan; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Oscillator; phase noise; sum-product algorithm SPA ; random matrix theory; variational Bayesian method; massive MIMO; symbol error probability; maximum a posteriori MAP detection; constellations; extended Kalman filter EKF ; maximum likelihood ML detection; mutual information; multiple-input multiple-output MIMO ; factor graph; free probability.;

    Sammanfattning : The mobile industry is preparing to scale up the network capacity by a factor of 1000x in order to cope with the staggering growth in mobile traffic. As a consequence, there is a tremendous pressure on the network infrastructure, where more cost-effective, flexible, high speed connectivity solutions are being sought for. LÄS MER

  5. 39. Characterization of Small Antennas & Wireless Devices for MIMO Systems in Multipath & Line-of-Sight

    Författare :Ahmed Hussain; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; USRP; OTA; SDR; RIMP; TRP; TIS; Reverberation chamber; Rayleigh; MIMO; LOS; LTE; Throughput;

    Sammanfattning : The current thesis investigates over-the-air (OTA) performance characterization of small antennas and wireless terminals in rich isotropic multipath (RIMP) environment, as well as in pure line-of-sight (LOS) environment when taking into account the random positions and orientations of the mobile terminals caused by the realistic user behavior. The latest mobile wireless terminals such as smart phones and tablets can be used in any random orientation thereby making even a received LOS-component appear as a random voltage at the antenna ports over time. LÄS MER

  7. 40. Improving snow water equivalent estimates with ground penetrating radar by measuring on multiple channels

    Författare :Nils Sundström; Robert W. Jacobel; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

    Sammanfattning : Snow water equivalent (SWE) of a snowpack is often measured along well-chosen transects representative of an area of interest, such as a drainage basin, to capture spatial distribution of SWE, which is of great interest for many applications. For example, it is a useful input to the new generation of hydrological models used for snow melt run-off predictions. LÄS MER