Sökning: "covariance matrices"

Visar resultat 21 - 25 av 48 avhandlingar innehållade orden covariance matrices.

  1. 21. Spectrum Sensing Algorithms Based on Second-Order Statistics

    Författare :Erik Axell; Erik G. Larsson; Jan-Åke Larsson; Danyo Danev; Visa Koivunen; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Cognitive radio is a new concept of reusing spectrum in an opportunistic manner. Cognitive radio is motivated by recent measurements of spectrum utilization, showing unused resources in frequency, time and space. Introducing cognitive radios in a primary network inevitably creates increased interference to the primary users. LÄS MER

  3. 22. Parameter Estimation for Multisensor Signal Processing : Reduced Rank Regression, Array Processing and MIMO Communications

    Författare :Karl Werner; Sergiy Vorobyov; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signal processing; Signalbehandling;

    Sammanfattning : This thesis deals with three estimation problems motivated by spatial signal processing using arrays of sensors. All three problems are approached using tools from estimation theory, including asymptotical analysis of performance and Cramér-Rao lower bound; Monte Carlo methods are used to evaluate small sample performance. LÄS MER

  4. 23. On physical units in multivariate analysis

    Författare :Tord Rikte; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : comparatively stringent mathematical frame has been developed, where the behaviour of physical dimensions (like ``length'', ``mass'', and ``time'') and physical units (like 1 m [1 metre], 1 kg [1 kilogramme], and 1 s [1 second]) is modelled. Easy-to-apply conditions for additivity and multiplicativity of physcial matrices are presented. LÄS MER

  5. 24. Seismic tomography : Algorithms and applications

    Författare :Zhengsheng Yao; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Geophysics Specialized In Seismology; geofysik; med inriktning mot seismologi;

    Sammanfattning : A preferred algorithm for seismic tomography needs to have capabilities including computational efficiency, minimal computer memory requirements, easy regularization and nonuniqueness analysis. In this thesis, regularised recursive least squares for seismic tomography is developed. LÄS MER

  7. 25. Essays on univariate long memory models

    Författare :Johan Lyhagen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Statistics; Statistik; Statistics; Statistik; Statistics; statistik;

    Sammanfattning : This thesis consists of five papers dealing with univariate long memory modelsin time series analysis.The first paper examines the performance of information criteria when usedto determine the lag order of a long memory process. The results indicate thatinformation criteria cannot be used successfully for small sample sizes. LÄS MER