Sökning: "frequency estimation"

Visar resultat 16 - 20 av 376 avhandlingar innehållade orden frequency estimation.

  1. 16. Estimation and detection of transmission line characteristics in the copper access network

    Författare :Fredrik Lindqvist; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Digital subscriber line; DSL; line qualification; twisted-pair line; copper access network; cable modeling; crosstalk channel estimation; estimation; detection;

    Sammanfattning : The copper access-network operators face the challenge of developing and maintaining cost-effective digital subscriber line (DSL) services that are competitive to other broadband access technologies. The way forward is dictated by the demand of ever increasing data rates on the twisted-pair copper lines. LÄS MER

  3. 17. Grid frequency stability from a hydropower perspective

    Författare :Elin Dahlborg; Per Norrlund; Urban Lundin; Linn Saarinen; Katherine Elkington; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Frequency control; frequency stability; grid codes; hydropower; inertia; Kaplan unit; model validation; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : Many AC grids suffer from decreased frequency stability due to less system inertia. This has increased the risk of large-scale blackouts. This thesis and its papers address the frequency stability problem from a hydropower perspective.Grid frequency stability assessments often require accurate system inertia estimates. LÄS MER

  4. 18. Induction Machine Speed Estimation - Observations on Observers

    Författare :Bo Peterson; Industriell elektroteknik och automation; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; control engineering; robotics; Automation; Elektronik och elektroteknik; Electronics and Electrical technology; estimation; sensorless control; observer; induction machine; Automatiska system; robotteknik; reglerteknik;

    Sammanfattning : This work focuses on observers estimating flux linkage and speed for induction machines, mainly in the low speed region. With speed estimation, sensorless control is possible, meaning that the speed of induction machines without mechanical speed sensors can be controlled. LÄS MER

  5. 19. Channel Estimation and Prediction for 5G Applications

    Författare :Rikke Apelfröjd; Mikael Sternad; Emil Björnson; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Channel estimation; Channel prediction; Channel smoothing; Linear estimation; Kalman filter; Massive MIMO; Coordinated Multipoint transmission; Robust precoding; Predictor antennas; Limits of predictability; Long range predictions; Electrical Engineering with specialization in Signal Processing; Elektroteknik med inriktning mot signalbehandling;

    Sammanfattning : Accurate channel state information (CSI) is important for many candidate techniques of future wireless communication systems. However, acquiring CSI can sometimes be difficult, especially if the user equipment is mobile in which case the future channel realisations must be estimated/predicted. LÄS MER

  7. 20. On Receiver Algorithms for OFDM Systems

    Författare :Florent Munier; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quantisation; multicarrier modulation; Intercarrier Interference ICI ; Phase noise; Wiener process; orthogonal frequency division multiplexing OFDM ; estimation; fading channels; channel estimation; iterative decoding.;

    Sammanfattning : This thesis addresses the problem of designing a receiver for an Orthogonal FrequencyDivisionMultiplexing (OFDM)communication system operating over fading channels, taking into account the effects of hardware imperfections. We discuss solutions for efficiently estimating the parameters of a channel model and for compensating oscillator phase noise and analog to digital converter (ADC) quantisation errors at the receiver. LÄS MER