Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets

Electromagnetic spectrum is a natural resource and at present its use is regulated by fixed spectrum assignment policy. That is, spectrum is assigned to license holders or services on a long term basis for large geographical regions. This fixed channel allocation served well in the past but the rapi...

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Main Author: Manju Mathew
Other Authors: Annamalai Benjamin Premkumar
Format: Theses and Dissertations
Language:English
Published: 2012
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Online Access:https://hdl.handle.net/10356/50779
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-507792023-03-04T00:41:29Z Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets Manju Mathew Annamalai Benjamin Premkumar School of Computer Engineering Centre for Multimedia and Network Technology DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems Electromagnetic spectrum is a natural resource and at present its use is regulated by fixed spectrum assignment policy. That is, spectrum is assigned to license holders or services on a long term basis for large geographical regions. This fixed channel allocation served well in the past but the rapid and tremendous growth in wireless communication changed the entire scenario. Introduction of every new communication application, either military or civilian makes the spectrum more and more congested. Meanwhile, the spectrum allocated to specific users does not ensure it is being used effectively at all times. Measurement studies reveal that 15 to 85 percent of the licensed radio spectrum is relatively unutilized or under utilized in most of the geographical locations for a considerable amount of time. The limited available spectrum and its inefficient usage encouraged a new communication paradigm to exploit the radio frequency spectrum opportunistically. This new concept is termed Dynamic Spectrum Access (DSA). The technology that makes DSA possible is Cognitive Radio (CR) which was first suggested by Joseph Mitola. In fact, CR is an all-encompassing term for a wide variety of technologies that enable radios to achieve various levels of self configuration and different functionalities ranging from ubiquitous wireless access to DSA for a device centric interference management. DSA networks define the already existing licensed users as primary users or legacy users and CR as secondary user. CR, sits on top of Software Defined Radio (SDR) is an intelligent wireless system that adapts to its environments to utilize the spectrum by its secondary usage in a 'do no harm' fashion. In simple words, it senses the radio environment, detects vacant spectrum bands, decides the best spectrum and chooses the transmission scheme which insures minimum interference to adjacent legacy users. As DSA networks targets mainly the wideband spectrum, the transmission technology should mitigate multi-path frequency selective fading channel impairments and should have multi-user support. DOCTOR OF PHILOSOPHY (SCE) 2012-11-01T07:28:18Z 2012-11-01T07:28:18Z 2012 2012 Thesis Manju, M. (2012). Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/50779 10.32657/10356/50779 en 157 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems
spellingShingle DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems
Manju Mathew
Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets
description Electromagnetic spectrum is a natural resource and at present its use is regulated by fixed spectrum assignment policy. That is, spectrum is assigned to license holders or services on a long term basis for large geographical regions. This fixed channel allocation served well in the past but the rapid and tremendous growth in wireless communication changed the entire scenario. Introduction of every new communication application, either military or civilian makes the spectrum more and more congested. Meanwhile, the spectrum allocated to specific users does not ensure it is being used effectively at all times. Measurement studies reveal that 15 to 85 percent of the licensed radio spectrum is relatively unutilized or under utilized in most of the geographical locations for a considerable amount of time. The limited available spectrum and its inefficient usage encouraged a new communication paradigm to exploit the radio frequency spectrum opportunistically. This new concept is termed Dynamic Spectrum Access (DSA). The technology that makes DSA possible is Cognitive Radio (CR) which was first suggested by Joseph Mitola. In fact, CR is an all-encompassing term for a wide variety of technologies that enable radios to achieve various levels of self configuration and different functionalities ranging from ubiquitous wireless access to DSA for a device centric interference management. DSA networks define the already existing licensed users as primary users or legacy users and CR as secondary user. CR, sits on top of Software Defined Radio (SDR) is an intelligent wireless system that adapts to its environments to utilize the spectrum by its secondary usage in a 'do no harm' fashion. In simple words, it senses the radio environment, detects vacant spectrum bands, decides the best spectrum and chooses the transmission scheme which insures minimum interference to adjacent legacy users. As DSA networks targets mainly the wideband spectrum, the transmission technology should mitigate multi-path frequency selective fading channel impairments and should have multi-user support.
author2 Annamalai Benjamin Premkumar
author_facet Annamalai Benjamin Premkumar
Manju Mathew
format Theses and Dissertations
author Manju Mathew
author_sort Manju Mathew
title Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets
title_short Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets
title_full Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets
title_fullStr Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets
title_full_unstemmed Adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets
title_sort adaptive transmission schemes of cognitive radio for dynamic spectrum access using wavelets and multiwavelets
publishDate 2012
url https://hdl.handle.net/10356/50779
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