Topics in Spectrum Sensing for Cognitive Radio

Cognitive radio is a new concept of reusing licensed spectrum in an unlicensed manner. Cognitive radio is motivated by recent measurements of spectrum utilization, showing unused resources in frequency, time and space. The spectrum must be sensed to detect primary user signals, in order to allow cog...

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Main Author: Axell, Erik
Format: Others
Language:English
Published: Linköpings universitet, Kommunikationssystem 2009
Subjects:
Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-51748
http://nbn-resolving.de/urn:isbn:978-91-7393-523-4
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spelling ndltd-UPSALLA1-oai-DiVA.org-liu-517482017-01-14T05:16:48ZTopics in Spectrum Sensing for Cognitive RadioengAxell, ErikLinköpings universitet, KommunikationssystemLinköpings universitet, Tekniska högskolanLinköping : Linköping University Electronic Press2009TECHNOLOGYTEKNIKVETENSKAPCognitive radio is a new concept of reusing licensed spectrum in an unlicensed manner. Cognitive radio is motivated by recent measurements of spectrum utilization, showing unused resources in frequency, time and space. The spectrum must be sensed to detect primary user signals, in order to allow cognitive radios in a primary system. In this thesis we study some topics in spectrum sensing for cognitive radio. The fundamental problem of spectrum sensing is to discriminate samples that contain only noise from samples that contain a very weak signal embedded in noise. We derive detectors that exploit known structures of the signal, for the cases of an OFDM modulated signal and an orthogonal space-time block coded signal. We derive optimal detectors, in the Neyman-Pearson sense, for a few different cases when all parameters are known. Moreover we study detection when the parameters, such as noise variance, are unknown. We propose solutions the problem of unknown parameters. We also study system aspects of cognitive radio. More specifically, we investigate spectrum reuse of geographical spectrum holes in a frequency planned primary network. System performance is measured in terms of the achievable rate for the cognitive radio system. Simulation results show that a substantial sum-rate could be achieved if the cognitive radios communicate over small distances. However, the spectrum hole gets saturated quite fast, due to interference caused by the cognitive radios. Licentiate thesis, comprehensive summaryinfo:eu-repo/semantics/masterThesistexthttp://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-51748urn:isbn:978-91-7393-523-4Linköping Studies in Science and Technology. Thesis, 0280-7971 ; 1417application/pdfinfo:eu-repo/semantics/openAccess
collection NDLTD
language English
format Others
sources NDLTD
topic TECHNOLOGY
TEKNIKVETENSKAP
spellingShingle TECHNOLOGY
TEKNIKVETENSKAP
Axell, Erik
Topics in Spectrum Sensing for Cognitive Radio
description Cognitive radio is a new concept of reusing licensed spectrum in an unlicensed manner. Cognitive radio is motivated by recent measurements of spectrum utilization, showing unused resources in frequency, time and space. The spectrum must be sensed to detect primary user signals, in order to allow cognitive radios in a primary system. In this thesis we study some topics in spectrum sensing for cognitive radio. The fundamental problem of spectrum sensing is to discriminate samples that contain only noise from samples that contain a very weak signal embedded in noise. We derive detectors that exploit known structures of the signal, for the cases of an OFDM modulated signal and an orthogonal space-time block coded signal. We derive optimal detectors, in the Neyman-Pearson sense, for a few different cases when all parameters are known. Moreover we study detection when the parameters, such as noise variance, are unknown. We propose solutions the problem of unknown parameters. We also study system aspects of cognitive radio. More specifically, we investigate spectrum reuse of geographical spectrum holes in a frequency planned primary network. System performance is measured in terms of the achievable rate for the cognitive radio system. Simulation results show that a substantial sum-rate could be achieved if the cognitive radios communicate over small distances. However, the spectrum hole gets saturated quite fast, due to interference caused by the cognitive radios.
author Axell, Erik
author_facet Axell, Erik
author_sort Axell, Erik
title Topics in Spectrum Sensing for Cognitive Radio
title_short Topics in Spectrum Sensing for Cognitive Radio
title_full Topics in Spectrum Sensing for Cognitive Radio
title_fullStr Topics in Spectrum Sensing for Cognitive Radio
title_full_unstemmed Topics in Spectrum Sensing for Cognitive Radio
title_sort topics in spectrum sensing for cognitive radio
publisher Linköpings universitet, Kommunikationssystem
publishDate 2009
url http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-51748
http://nbn-resolving.de/urn:isbn:978-91-7393-523-4
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