A fast sensing algorithm for spectrum detection in cognitive radios

Cognitive Radio (CR) has emerged as a very promising solution to mitigate the scarcity in electromagnetic spectrum for wireless communication. CR promises to maximize the efficiency of spectrum utilization by seeking out spectral vacancies (holes) in the licensed band and using it for communication...

Full description

Saved in:
Bibliographic Details
Main Author: Prashob Ramachandran Nair
Other Authors: Vinod Achutavarrier Prasad
Format: Theses and Dissertations
Language:English
Published: 2012
Subjects:
Online Access:https://hdl.handle.net/10356/48179
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Nanyang Technological University
Language: English
id sg-ntu-dr.10356-48179
record_format dspace
spelling sg-ntu-dr.10356-481792023-03-04T00:45:12Z A fast sensing algorithm for spectrum detection in cognitive radios Prashob Ramachandran Nair Vinod Achutavarrier Prasad School of Computer Engineering Centre for High Performance Embedded Systems DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems Cognitive Radio (CR) has emerged as a very promising solution to mitigate the scarcity in electromagnetic spectrum for wireless communication. CR promises to maximize the efficiency of spectrum utilization by seeking out spectral vacancies (holes) in the licensed band and using it for communication purposes. Thus sensing of the spectrum to detect the vacant holes forms an integral part of a CR system. The performance of a cognitive radio system depends on how well it can maximize the usage of a vacant frequency band without causing any interference to the licensed user, also called the primary user. Thus the ability to detect a primary user as well as to avoid any false alarm is of paramount importance for such a system. There are various techniques to examine the presence of a communication signal in a given frequency band. The easiest and most widespread of these is the energy based detection. In this technique, the energy of the received samples is computed and compared with a predetermined threshold. If the total energy of the received samples is more than the computed threshold, the frequency band is assumed to be occupied by the licensed user. The selection of the threshold to discriminate between the binary hypothesis of presence and absence of primary user signal plays a very vital role in determining the accuracy of the spectrum sensing algorithms. Conventionally, for an energy detector (ED) based CR, the threshold is set based on estimated noise power and this is not changed even though the CR may have more information available about the channel. It has been observed that for a conventional energy detector based CR at low signal-to-noise ratio (SNR), when the time to sense the spectrum is short, the ability to detect the presence of the primary user deteriorates significantly. However, if the threshold is chosen based on the target probability of detection, then there is a significant improvement in the ability of the CR to detect the presence of the primary user. MASTER OF ENGINEERING (SCE) 2012-03-27T06:02:55Z 2012-03-27T06:02:55Z 2012 2012 Thesis Prashob, R. N. (2012). A fast sensing algorithm for spectrum detection in cognitive radios. Master’s thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/48179 10.32657/10356/48179 en 103 p. application/pdf application/pdf 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
Prashob Ramachandran Nair
A fast sensing algorithm for spectrum detection in cognitive radios
description Cognitive Radio (CR) has emerged as a very promising solution to mitigate the scarcity in electromagnetic spectrum for wireless communication. CR promises to maximize the efficiency of spectrum utilization by seeking out spectral vacancies (holes) in the licensed band and using it for communication purposes. Thus sensing of the spectrum to detect the vacant holes forms an integral part of a CR system. The performance of a cognitive radio system depends on how well it can maximize the usage of a vacant frequency band without causing any interference to the licensed user, also called the primary user. Thus the ability to detect a primary user as well as to avoid any false alarm is of paramount importance for such a system. There are various techniques to examine the presence of a communication signal in a given frequency band. The easiest and most widespread of these is the energy based detection. In this technique, the energy of the received samples is computed and compared with a predetermined threshold. If the total energy of the received samples is more than the computed threshold, the frequency band is assumed to be occupied by the licensed user. The selection of the threshold to discriminate between the binary hypothesis of presence and absence of primary user signal plays a very vital role in determining the accuracy of the spectrum sensing algorithms. Conventionally, for an energy detector (ED) based CR, the threshold is set based on estimated noise power and this is not changed even though the CR may have more information available about the channel. It has been observed that for a conventional energy detector based CR at low signal-to-noise ratio (SNR), when the time to sense the spectrum is short, the ability to detect the presence of the primary user deteriorates significantly. However, if the threshold is chosen based on the target probability of detection, then there is a significant improvement in the ability of the CR to detect the presence of the primary user.
author2 Vinod Achutavarrier Prasad
author_facet Vinod Achutavarrier Prasad
Prashob Ramachandran Nair
format Theses and Dissertations
author Prashob Ramachandran Nair
author_sort Prashob Ramachandran Nair
title A fast sensing algorithm for spectrum detection in cognitive radios
title_short A fast sensing algorithm for spectrum detection in cognitive radios
title_full A fast sensing algorithm for spectrum detection in cognitive radios
title_fullStr A fast sensing algorithm for spectrum detection in cognitive radios
title_full_unstemmed A fast sensing algorithm for spectrum detection in cognitive radios
title_sort fast sensing algorithm for spectrum detection in cognitive radios
publishDate 2012
url https://hdl.handle.net/10356/48179
_version_ 1759858073578504192