Sökning: "I Q modulator"

Visar resultat 6 - 9 av 9 avhandlingar innehållade orden I Q modulator.

  1. 6. CALLUM Linear Transmitter - Architecture and Circuit Analysis

    Författare :Roland Strandberg; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Telekommunikationsteknik; Telecommunication engineering; loop time delay; modulation negative feedback; spectral emissions; baseband model; CALLUM; Linear transmitter architecture; power amplifier linearization;

    Sammanfattning : This doctoral dissertation presents a study of linear radio transmitters based on the combined analog locked loop universal modulator (CALLUM) approach. Linear architectures such as CALLUM are very attractive for power-efficient operations, since they have no fundamental limitations prohibiting a 100% efficiency for all envelope levels, without sacrificing the potential of a linear transmission. LÄS MER

  3. 7. Digital Predistortion Linearization of High Efficiency Transmitters

    Författare :Haiying Cao; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : High efficiency and good linearity are two important characteristics of transmitters in future wireless communication systems. However, there is usually a trade-off: when high efficiency is achieved, linearity is degraded and nonlinear distortion occurs. LÄS MER

  4. 8. Signaling for Optical Intensity Channels

    Författare :Johnny Karout; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lattice codes; mutual information; intensity modulation; noncoherent communications; Direct detection; sphere packing.; infrared communications; free-space optical communications; fiber-optical communications;

    Sammanfattning : With the growing popularity of social media services, e-commerce, and many other internet-based services, we are witnessing a rapid growth in the deployment of data centers and cloud computing platforms. As a result, the telecommunications industry has to continue providing additional network capacity to meet the increasing demand for bandwidth. LÄS MER

  5. 9. Transmitter Linearization for mm-Wave Communications Systems

    Författare :Halil Volkan Hünerli; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; linearization; transmitter; mm-wave power amplifier; Eband; analog predistorter; digital predistortion;

    Sammanfattning : There is an ever increasing need for enabling higher data rates in modern communication systems which brings new challenges in terms of the power consumption and nonlinearity of hardware components. These problems become prominent in power amplifiers (PAs) and can significantly degrade the performance of transmitters, and hence the overall communication system. LÄS MER