Enhancement of Space-Time Receiver Structure with Multiuser Detection for Wideband CDMA Communication Systems

Wideband CDMA (WCDMA) which has been accepted as one of the radio access technology for third generation (3G) systems has many advantages such as efficient spectrum utilization and variable user data rates. However, multiple access interference (MAI) is a major constraint limiting the capacity of...

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Main Author:	Subramaniam, Jeevan Rao
Format:	Thesis
Language:	English English
Published:	2006
Subjects:	Broadband communication systems - Case studies Telecommunication system
Online Access:	http://psasir.upm.edu.my/id/eprint/208/1/549041_FK_2006_32.pdf
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spelling	my-upm-ir.2082013-05-27T06:46:34Z Enhancement of Space-Time Receiver Structure with Multiuser Detection for Wideband CDMA Communication Systems 2006-03 Subramaniam, Jeevan Rao Wideband CDMA (WCDMA) which has been accepted as one of the radio access technology for third generation (3G) systems has many advantages such as efficient spectrum utilization and variable user data rates. However, multiple access interference (MAI) is a major constraint limiting the capacity of the system. Multiuser detection and smart antenna technologies are capable of increasing the system capacity through mitigation of such impairment. In this thesis, a combination of spatial signal processing with temporal signal processing is proposed. Additionally, the space-time receiver structure is combined with multiuser detection to further enhance the system. We propose and analyze different combined space-time linear multiuser detection configurations in an uplink mobile radio communications channel that incorporates the spatial temporal parameters. The performance of these receivers is evaluated as a function of the number of antenna elements, Rake fingers and number of users. We consider two different pilot symbol assisted adaptive beamforming algorithms, Least Mean Square (LMS) and Recursive Least Square (RLS). The algorithms are used to adjust the weights of the antenna array to form the appropriate beam patterns to track the desired user and null interfering users. The adaptive algorithms are evaluated as a function of the number of iterations it takes to converge and its transmission performance are compared. Additionally, two different linear multiuser detection techniques, Decorrelator and linear Minimum Mean Square Error (MMSE) strategies are used in conjunction with the combined receiver structure.The proposed combined Space Time Multiuser Detector which is suitable for WCDMA systems is shown to provide significant gain in transmission performance and system capacity. It is shown via simulation that the combined RLS adaptive algorithm with the linear MMSE multiuser detector provides the best overall performance. The simulation result also shows that the combined receiver structure is robust in the presence of strong interference due to high data rate users. Broadband communication systems - Case studies Telecommunication system 2006-03 Thesis http://psasir.upm.edu.my/id/eprint/208/ http://psasir.upm.edu.my/id/eprint/208/1/549041_FK_2006_32.pdf application/pdf en public masters Universiti Putra Malaysia Broadband communication systems - Case studies Telecommunication system Faculty of Engineering English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
topic	Broadband communication systems - Case studies Telecommunication system
spellingShingle	Broadband communication systems - Case studies Telecommunication system Subramaniam, Jeevan Rao Enhancement of Space-Time Receiver Structure with Multiuser Detection for Wideband CDMA Communication Systems
description	Wideband CDMA (WCDMA) which has been accepted as one of the radio access technology for third generation (3G) systems has many advantages such as efficient spectrum utilization and variable user data rates. However, multiple access interference (MAI) is a major constraint limiting the capacity of the system. Multiuser detection and smart antenna technologies are capable of increasing the system capacity through mitigation of such impairment. In this thesis, a combination of spatial signal processing with temporal signal processing is proposed. Additionally, the space-time receiver structure is combined with multiuser detection to further enhance the system. We propose and analyze different combined space-time linear multiuser detection configurations in an uplink mobile radio communications channel that incorporates the spatial temporal parameters. The performance of these receivers is evaluated as a function of the number of antenna elements, Rake fingers and number of users. We consider two different pilot symbol assisted adaptive beamforming algorithms, Least Mean Square (LMS) and Recursive Least Square (RLS). The algorithms are used to adjust the weights of the antenna array to form the appropriate beam patterns to track the desired user and null interfering users. The adaptive algorithms are evaluated as a function of the number of iterations it takes to converge and its transmission performance are compared. Additionally, two different linear multiuser detection techniques, Decorrelator and linear Minimum Mean Square Error (MMSE) strategies are used in conjunction with the combined receiver structure.The proposed combined Space Time Multiuser Detector which is suitable for WCDMA systems is shown to provide significant gain in transmission performance and system capacity. It is shown via simulation that the combined RLS adaptive algorithm with the linear MMSE multiuser detector provides the best overall performance. The simulation result also shows that the combined receiver structure is robust in the presence of strong interference due to high data rate users.
format	Thesis
qualification_level	Master's degree
author	Subramaniam, Jeevan Rao
author_facet	Subramaniam, Jeevan Rao
author_sort	Subramaniam, Jeevan Rao
title	Enhancement of Space-Time Receiver Structure with Multiuser Detection for Wideband CDMA Communication Systems
title_short	Enhancement of Space-Time Receiver Structure with Multiuser Detection for Wideband CDMA Communication Systems
title_full	Enhancement of Space-Time Receiver Structure with Multiuser Detection for Wideband CDMA Communication Systems
title_fullStr	Enhancement of Space-Time Receiver Structure with Multiuser Detection for Wideband CDMA Communication Systems
title_full_unstemmed	Enhancement of Space-Time Receiver Structure with Multiuser Detection for Wideband CDMA Communication Systems
title_sort	enhancement of space-time receiver structure with multiuser detection for wideband cdma communication systems
granting_institution	Universiti Putra Malaysia
granting_department	Faculty of Engineering
publishDate	2006
url	http://psasir.upm.edu.my/id/eprint/208/1/549041_FK_2006_32.pdf
_version_	1747810174456823808

Enhancement of Space-Time Receiver Structure with Multiuser Detection for Wideband CDMA Communication Systems

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