Sökning: "Rayleigh fading"

Visar resultat 21 - 25 av 56 avhandlingar innehållade orden Rayleigh fading.

1. 21. Fading Channels: Capacity and Channel Coding Rate in the Finite-Blocklength Regime

   Författare :Wei Yang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Information-theoretic studies on the fundamental limits of communication over wireless fading channels typically rely on simplifying assumptions, such as perfect channel state information (CSI), infinite blocklength, and vanishing probability of error. Although these assumptions are reasonable for most of the current wireless communication systems, they may be inaccurate for next-generation wireless systems. LÄS MER

3. 22. The Block Error Rate in Block Interference Channels and its Applications to Medium Access Control

   Författare :Arash Tahmasebi Toyserkani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; throughput; wireless sensor networks; TDMA; block fading channels; Block error rate; scheduling; ALOHA; medium access control;

   Sammanfattning : This thesis may be distinguished into two interdependentparts. The first part outlines the outcome of our efforts toconstruct accurate and yet simple models that account for the probability of successful reception of a packet for a wide range of physical layer parameters. LÄS MER

4. 23. Ultra-Reliable Short-Packet Communications: Fundamental Limits and Enabling Technologies

   Författare :Johan Östman; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultra-reliable low-latency; variablelength stop-feedback; imperfect CSI; channel estimation; HARQ.; joint detection and decoding; short packets; Block-fading channels; multiuser massive MIMO;

   Sammanfattning : The paradigm shift from 4G to 5G communications, anticipated to enable ultra-reliable low-latency communications (URLLC), will enforce a radical change in the design of wireless communication systems. Unlike in 4G systems, where the main objective is to provide a large transmission rate, in URLLC, as implied by its name, the objective is to enable transmissions with low latency and, simultaneously, very high reliability. LÄS MER

5. 24. Serially Concatenated Space-Time Coded Continuous Phase Modulation

   Författare :Dhammika Bokolamulla; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; serially concatenated codes; symbol-by-symbol {MAP} detection; factor graphs; sum-product algorithm; Iterative detection; multiuser detection; space-time codes; continuous phase modulation;

   Sammanfattning : Certain problems associated with reliable digital wireless communication over a frequency-flat slow Rayleigh fadingchannel are treated, when the transmitted signal is modulated using continuous phase modulation (CPM) due to the desirable properties of CPM. The primary focus of attention is on detection strategies, and the thesis proposes iterative detection algorithms for CPM signals transmitted over frequency-flat slow Rayleigh fading channels. LÄS MER

7. 25. Wireless Sensor Network and Radio Wave Propagation in Harsh Environments

   Författare :Mathias Grudén; Anders Rydberg; Erik Björnemo; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless Sensor Network; WISENET; Wave Propagation; Radio Communication; Harsh Environmnents; Engineering Science with specialization in Microwave Technology; Teknisk fysik med inriktning mot mikrovågsteknik;

   Sammanfattning : This licentiate thesis cover two important subjects regarding the application of wireless sensor networks (WSNs). Both subjects are related to propagation mechanisms. The first subject is what the radio channel looks like and how it behaves. LÄS MER