Sökning: "Quadrature Signals"

Visar resultat 21 - 25 av 25 avhandlingar innehållade orden Quadrature Signals.

1. 21. Digital Compensation Techniques for Power Amplifiers in Radio Transmitters

   Författare :Jessica Chani Cahuana; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear system; linearization; power amplifier; iterative learning control; digital predistortion; Volterra series;

   Sammanfattning : Power amplifiers (PAs) are vital components in radio transmitters because they are responsible to amplify the low power communication signals to power levels suitable for transmission. Important requirements of PAs are high efficiency and linearity. Unfortunately, there is a tradeoff between efficiency and linearity. LÄS MER

3. 22. On the labeling of Signal Constellations

   Författare :Johan Lassing; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The work in this thesis studies a simple model of a digital communication system in which the transmitter operates on a sequence of information bits by grouping them into blocks of m bits and mapping such blocks onto one out of M = 2m waveforms, which is transmitted over the channel. The receiver recovers the original message by demapping the transmitted signals disturbed by noise back to m-bit blocks using maximum-likelihood symbol detection. LÄS MER

4. 23. Microwave CMOS VCOs and Front-Ends - using integrated passives on-chip and on-carrier

   Författare :Markus Törmänen; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VCO; mixer; microwave; LNA; CMOS; front-end; System-on-Package;

   Sammanfattning : The increasing demand for high data rates in wireless communication systems is increasing the requirements on the transceiver front-ends, as they are pushed to utilize more and wider bands at higher frequencies. The work in this thesis is focused on receiver front-ends composed of Low Noise Amplifiers (LNAs), Mixers, and Voltage Controlled Oscillators (VCOs) operating at microwave frequencies. LÄS MER

5. 24. Study of Six-Port Modulators and Demodulators for High-Speed Data Communications

   Författare :Joakim Östh; Shaofang Gong; Magnus Karlsson; Robert Weigel; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : There is an increasing demand for high-speed wireless data communications to support consumers’ need for, among other things, real time streaming of high definition video and fast file transfers. One radio architecture that has a potential to meet the increasing demand for high-speed data communications is a radio technique based on the six-port architecture. LÄS MER

7. 25. A Tensor Framework for Multidimensional Signal Processing

   Författare :Carl-Fredrik Westin; Gösta Granlund; Linköpings universitet; []
   Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : This thesis deals with ltering of multidimensional signals. A large part of the thesis is devoted to a novel filtering method termed "Normalized convolution". The method performs local expansion of a signal in a chosen lter basis which not necessarily has to be orthonormal. LÄS MER