Sökning: "orthogonal frequency-division multiplexing"

Visar resultat 21 - 25 av 45 avhandlingar innehållade orden orthogonal frequency-division multiplexing.

1. 21. Contributions to Frequency Offset and Time Delay Estimation

   Författare :Mattias Olsson; Håkan Johansson; Jonny Holmberg; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; time delay estimation; OFDM; carrier frequency offset; Signal processing; Signalbehandling;

   Sammanfattning : The demand for reliable high rate and efficient communication is ever increasing. In this thesis we look at two different problems in such systems, and their possible solutions. LÄS MER

3. 22. Spectrally Precoded OFDM-Design and Analysis

   Författare :Medhat Mohamad; Jaap van de Beek; Rickard Nilsson; Mérouane Debbah; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; OFDM; spectral precoding; out of band emission; 5G; Signalbehandling; Signal Processing;

   Sammanfattning : Despite shifting towards mm-wave bands, the sub-6 GHz band will continue to be a fundamental spectral band in 5G. However, the severe congestion in this band makes a well-constrained spectrum a critical requirementof 5G. LÄS MER

4. 23. Enhancing Radio Frequency System Performance by Digital Signal Processing

   Författare :Charles Nader; Peter Händel; Niclas Björsell; Thomas Eriksson; Högskolan i Gävle; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronics; Elektronik;

   Sammanfattning : In this thesis measurement systems for the purpose of characterization of radio frequency power amplifiers are studied. Methods to increase the speed, accuracy, bandwidth, as well as to reduce the sampling requirements and testing cost are presented. LÄS MER

5. 24. Channel Estimation and Prediction for MIMO OFDM Systems : Key Design and Performance Aspects of Kalman-based Algorithms

   Författare :Daniel Aronsson; Mikael Sternad; Ove Edfors; Uppsala universitet; []
   Nyckelord :channel estimation; channel prediction; OFDM; Kalman filtering; Electrical Engineering with specialization in Signal Processing; Elektroteknik med inriktning mot signalbehandling;

   Sammanfattning : Wireless broadband systems based on Orthogonal Frequency Division Multiplexing (OFDM) are being introduced to meet demands for high data transfer rates. In multiple users systems, the available bandwidth has to be shared efficiently by several users. The radio channel quality will fluctuate, or fade, as users move. LÄS MER

7. 25. Ultra-wideband Antenna and Radio Front-end Systems

   Författare :Magnus Karlsson; Anders Rydberg; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless communication; ultra-wideband; radio communication; UWB bandwidth; antenna parallelism; Electrical engineering; Elektroteknik;

   Sammanfattning : The number of wireless communication applications increase steadily, leading to the competition for currently allocated frequency bands. Pressure on authorities around the world to permit communications in higher and wider frequency ranges to achieve higher wireless capacity than those existed in the past has resulted in several new specifications. LÄS MER