Sökning: "flat fading channel"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden flat fading channel.

  1. 1. Constellation Design under Channel Uncertainty

    Författare :Jochen Giese; Mikael Skoglund; Bertrand Hochwald; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Constellation design; diversity; fading channels; frequency-selective channels; joint channel estimation and data detection; multiple antennas; partial channel state information; wireless communication; Telecommunication; Telekommunikation;

    Sammanfattning : The topic of this thesis is signaling design for data transmission through wireless channels between a transmitter and a receiver that can both be equipped with one or more antennas. In particular, the focus is on channels where the propagation coefficients between each transmitter--receiver antenna pair are only partially known or completetly unknown to the receiver and unknown to the transmitter. LÄS MER

  3. 2. Design of Wireless Communication Systems -- Issues on Synchronization, Channel Estimation and Multi-Carrier Systems

    Författare :Fredrik Tufvesson; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pre-compensation; pilot pattern; Elektronik; orthogonal frequency division multiplex; Wireless; synchronization; detection; preambles; channel estimation; Electronics; superimposed pilot sequences; sub-channel bandwidth; precoding;

    Sammanfattning : This thesis deals with certain aspects in the design of wireless communications systems. It is focused on problems related to the mobile or wireless channel: synchronization, channel estimation and design of wireless orthogonal frequency division multiplex (OFDM) systems. LÄS MER

  4. 3. Channel Estimation in Wireless Communication Systems Employing Multiple Antennas

    Författare :Mikael Coldrey; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiple antennas; capacity; channel estimation; non-parametric estimation; training; distributed sources; MIMO; Wireless communications; superimposed pilots; performance bounds;

    Sammanfattning : Antennas that are able to adaptively direct the transmitted (and received) energy are of great interest in future wireless communication systems. The directivity implies reduced transmit power and interference, and also a potential for increased capacity. LÄS MER

  5. 4. Efficient Digital Communication over the Time Continuous Rayleigh Fading Channel

    Författare :Ulf Hansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Frequency flat, fast Rayleigh fading may be considered the most critical disturbance in a wireless communication system. In its most general form, it is modeled as a multiplicative time continuous random (zero mean complex Gaussian) distortion of the transmitted signal. LÄS MER

  7. 5. On Bit-Wise Decoders for Coded Modulation

    Författare :Mikhail Ivanov; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bit-error probability; L-values; labeling; Gray code; coded modulation; log-likelihood ratio; maximum likelihood decoder; Additive white Gaussian noise; quadrature amplitude modulation.; interleaver; flat fading channel; pairwise error probability;

    Sammanfattning : Coded modulation is a technique that emerged as a response to the growing demand for high data rates. It was devised to achieve high spectral efficiency with high reliability, potentially approaching Shannon’s capacity. The main idea of coded modulation consists in combining error-correcting coding with higher-order modulation. LÄS MER