Download or read book Multirate Schemes and Multiuser Decoding in DS CDMA Systems written by Tony Ottosson and published by . This book was released on 1995 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frequency Domain Multiuser Detection for CDMA Systems written by Dr. Paulo Silva and published by River Publishers. This book was released on 2012-02-25 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Future broadband wireless communication systems are expected to be able to offer new and powerful services enabling fast transmission rates of several tens of Mbit/s. This is an ambitious challenge especially for mobile communication systems since these systems should be able to cope with severely time dispersive channels, associated to the signal multipath propagation. Moreover, these systems should have high spectral and power efficiencies, as well as high capacity and flexibility. Spread spectrum techniques, particularly coded division multiple access (CDMA) techniques allow high capacity and flexibility, continuous transmission requiring low-peak power requirements for the amplifiers, as well as some robustness against fading and time-dispersion effects associated with the multipath propagation. When employed in prefix assisted (PA) block transmission schemes combined with frequency-domain receiver implementations they become especially interesting for broadband wireless systems. In Frequency-Domain Multiuser Detection for CDMA Systems the use of PA block transmission is considered in the context of both DS (Direct Sequence) and MC (Multicarrier) CDMA schemes. The main goal is the study of frequency-domain multiuser detection techniques with iterative signal detection/decoding techniques, also in combination with estimation and cancelation of nonlinear distortion effects. The receiver structures are suitable to scenarios with high interference levels and strongly time-dispersive channels.

Download or read book Multi user Detection for Multi rate DS CDMA Systems written by Jinwen Ma and published by . This book was released on 2000 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless cellular communication is witnessing a rapid growth in market, technology and range of services. Current and future demands for wireless communication services motivate the need for handling multi-media traffic types. In a multimedia communication system, users with different and even time-varying rates and quality of services (QoS) requirements, such as voice, image and data, must be accommodated. The use of Spread Spectrum modulation with Code Division Multiple Access (CDMA) technology is an attractive approach for economical spectrally efficient and high quality cellular and personal communication services. This dissertation explores the technologies of applying different interference cancellation techniques to multi-rate CDMA systems that serve users with different QoS. Multiple Access Interference (MAI) and multipath propagation are the major issues in wireless communication systems. It is also true for multi-rate CDMA systems. Multi-user detection has been shown to be effective in combating the near-far problem and providing superior performance over conventional detection method. In this dissertation, we combine both linear minimum mean squared error (LMMSE) detector, nonlinear decision feedback detector, with other signal processing techniques, such as array processing and multipath combining, to create effective near-far resistant detectors for multi-rate CDMA systems. Firstly, we propose MMSE receivers for synchronous multi-rate CDMA system and compare the performance with the corresponding multi-rate decorrelating detectors. The multi-rate decorrelating detector is optimally near-far resistant and easy to implement. The proposed linear MMSE multi-rate receiver can be adaptively implemented only with the knowledge of the desired user. Due to the fact that MMSE detector offers best trade-off between the MAI cancellation and noise variance enhancement, it is shown that multi-rate MMSE receiver can offer better performance than the multi-rate decorrelator when the interfering users' Signal to Noise Ratio (SNR) is relatively low comparing to the desired user's SNR. Secondly, the asynchronous multi-rate CDMA system, we propose multi-rate multi-shoot decorrelating detectors and multi-rate multi-shot MMSE detectors. The performance of multi-shot detectors can be improved monotonically with increasing the number of stacked bits, but a great computational complexity is going to be introduced in order to get better performance. A debiasing method is introduced to multi-rate multi-shot linear detectors. Debiasing method optimizes multi-rate detectors based on the multi-rate multi-shot model. Debiasing multi-shot MMSE detector for multi-rate signals can offer performance than the corresponding debiasing multi-shot decorrelating detector. Thirdly, we propose linear space-time receivers for multi-rate CDMA systems. The minimum mean-squared error criteria is used. We perform a comparative study on the multi-rate receiver which uses either multipath (temporal) processing or array (spatial) processing, and the one which uses both array and multipath (space-time) processing. The space-time receiver for the multi-rate CDMA signals give us the potential of improving the capacity of multi-rate systems. The space-time processing combined with multiuser detection have the advantages of combating multipath fading through temporal processing, reducing MAI through MMSE method and provide antenna or diversity gain through spatial processing and increasing the capacity of the multi-rate CDMA systems. Lastly, the group-wise interference cancellation methods are proposed for multi-rate CDMA signals. The non-linear decision feedback detection (DFD) schemes are used in the proposed receivers. The proposed interference cancellation schemes benefit from the nature of the unequal received amplitudes for multi-rate CDMA signals. Users with same data rate are grouped together. Users with the highest data-rate are detected first. Interference between the groups is cancelled in a successive order. The results show that the group-wise MMSE DFD yields better performance than multi-rate linear MMSE detector and multi-rate decorrelating detector, especially for highly loaded CDMA systems.

Download or read book Coding Modulation and Multiuser Decoding for DS CDMA Systems written by Tony Ottosson and published by . This book was released on 1997 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings Exhibition future Access written by and published by . This book was released on 1997 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coordinated Multiuser Communications written by CHRISTIAN SCHLEGEL and published by Springer Science & Business Media. This book was released on 2006-07-10 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coordinated Multiuser Communications provides for the first time a unified treatment of multiuser detection and multiuser decoding in a single volume. Many communications systems, such as cellular mobile radio and wireless local area networks, are subject to multiple-access interference, caused by a multitude of users sharing a common transmission medium. The performance of receiver systems in such cases can be greatly improved by the application of joint detection and decoding methods. Multiuser detection and decoding not only improve system reliability and capacity, they also simplify the problem of resource allocation. Coordinated Multiuser Communications provides the reader with tools for the design and analysis of joint detection and joint decoding methods. These methods are developed within a unified framework of linear multiple-access channels, which includes code-division multiple-access, multiple antenna channels and orthogonal frequency division multiple access. Emphasis is placed on practical implementation aspects and modern iterative processing techniques for systems both with, and without integrated error control coding. Focusing on the theory and practice of unifying accessing and transmission aspects of communications, this book is a valuable reference for students, researchers and practicing engineers.

Download or read book Multi Carrier and Spread Spectrum Systems written by Khaled Fazel and published by John Wiley & Sons. This book was released on 2008-09-15 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The technological progress in multi-carrier (MC) modulation led orthogonal frequency division multiplexing (OFDM) to become an important part of beyond 3G cellular mobile communication standards, including LTE and WiMAX. In addition, the flexibility offered by the spread spectrum (SS) and time division multiplexing (TDM) techniques motivated many researchers to investigate several MC combined multiple access schemes, such as MC-CDMA, OFDMA and MC-TDMA. These schemes benefit from the advantages of each sub-system and offer high flexibility, high spectral efficiency, simple detection strategies and narrow-band interference rejection capability. Multi-Carrier and Spread Spectrum Systems is one of the first books to describe and analyze the basic concepts of multi-carrier OFDM transmission and its combination with spread spectrum (MC-CDMA). The different architectures and detection strategies as well as baseband-related transceiver components are explained. This includes topics like FEC channel coding and decoding, modulation and demodulation (IFFT/FFT), digital I/Q-generation, time and frequency synchronisation, channel estimation, frequency domain equalization and RF aspects such as phase noise and non-linearity issues. Concrete examples of its applications for cellular mobile communication systems (B3G/4G) are given. Further derivatives of MC-SS (such as OFDMA, SS-MC-MA and DFT-spread OFDM) and their corresponding applications in the LTE, WiMAX, WLAN and DVB-RCT standards are detailed. Capacity and flexibility enhancements of multi-carrier OFDM systems by different MIMO diversity techniques such as space time/frequency coding (STC, SFC) and software defined radio concepts are also described. Written in a highly accessible manner this book provides a unique reference on the topics of multi-carrier and spread spectrum communications, assisting 4G engineers with their implementation. Fully updated new edition of successful text, including two new chapters on LTE and WiMAX Describes in detail new applications of OFDM in mobile communication standards Examines all multi-carrier spread spectrum schemes, with in-depth analysis, from theory to practice Introduces the essentials of important wireless standards based on multi-carrier/spread spectrum techniques.

Download or read book 2002 IEEE Seventh International Symposium on Spread Spectrum Techniques and Applications Prague Czech Republic September 2 5 2002 written by and published by . This book was released on 2002 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wireless Information Networks written by Jack M. Holtzman and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: In April 1995, WINLAB (the Wireless Infonnation Network Lab oratory at Rutgers University) hosted the Fifth WINLAB Workshop on Third Generation Wireless Infonnation Networks. This workshop brings together a select group of experts interested in the future of Personal Communications, Mobile Computing and other services supported by wireless communications. As a sequel to Kluwer books on previous WINLAB workshops,l this volume assembles written versions of presentations of the Fifth Workshop. The last few years have been exciting for the field of wireless communications. The second generation systems that have absorbed our attention during those years are becoming commercial realities. Everyone is looking forward to PCS, especially in light of the recent auctions. We see an explosion of technical alternatives for meeting the demand for wireless communications. We also have applications in search of the best technologies rather than the reverse. The papers included provide new insights into many of the issues needing resolution for the successful introduction of the new services by the end of the decade. The authors represent views from both industry and universities from a number of nations. They are grouped into four main categories: Architecture, Radio Resource Management, Access, and Mobile Data, Mobile Networks.

Download or read book Conference Proceedings written by and published by . This book was released on 2004 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IEEE International Conference on Personal Wireless Communications written by and published by . This book was released on 1997 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiuser Code timing Acquisition for DS CDMA Systems written by Rensheng Wang and published by . This book was released on 2005 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wiley Encyclopedia of Telecommunications Volume 4 written by John G. Proakis and published by Wiley-Interscience. This book was released on 2003 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Contains 275 tutorial articles focused on modern telecommunications topics. The contents include articles on communication networks, source coding and decoding, channel coding and decoding, modulation and demodulation, optical communications, satellite communications, underwater acoustic communications, radio propagation, antennas, multiuser communications, magnetic storage systems, and a variety of standards"--V.1, p. v.

Download or read book Blind Detection Parameters Estimation and Despreading of DS CDMA Signals in Multirate Multiuser Cognitive Radio Systems written by Crepin Nsiala Nzeza and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Blind Detection, Parameters Estimation and Despreading of DS-CDMA Signals in Multirate Multiuser Cognitive Radio Systems.

Download or read book WCDMA written by Tero Ojanperä and published by Artech House. This book was released on 2001 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: While covering the basics of wideband CDMA, the key UMTS technology, this major revision of the best-selling Wideband CDMA for Third Generation Mobile Communications brings you up-to-date with all the latest developments in third generation mobile communications. New sections cover fundamental IP concepts, All-IP core networks, and WCDMA, EDGE and cdma2000 technologies, including their future developments - WCDMA HSPA and 1XEV. The book gives you a complete understanding of the complex standardization environment of 3G networks and the design and development of 3G systems. It describes how third generation system applications impact radio access system design and compares and contrasts major wideband CDMA standards: WCDMA, WCDMA TDD and cdma2000. Includes 190 illustrations and 75 equations.

Download or read book Wireless Communications Resource Management written by Byeong Gi Lee and published by John Wiley & Sons. This book was released on 2009-07-28 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless technologies continue to evolve to address the insatiable demand for faster response times, larger bandwidth, and reliable transmission. Yet as the industry moves toward the development of post 3G systems, engineers have consumed all the affordable physical layer technologies discovered to date. This has necessitated more intelligent and optimized utilization of available wireless resources. Wireless Communications Resource Managem ent, Lee, Park, and Seo cover all aspects of this critical topic, from the preliminary concepts and mathematical tools to detailed descriptions of all the resource management techniques. Readers will be able to more effectively leverage limited spectrum and maximize device battery power, as well as address channel loss, shadowing, and multipath fading phenomena. Presents the latest resource allocation techniques for new and next generation air interface technologies Arms readers with the necessary fundamentals and mathematical tools Illustrates theoretical concepts in a concrete manner Gives detailed coverage on scheduling, power management, and MIMO techniques Written by an author team working in both academia and industry Wireless Communications Resource Managementis geared for engineers in the wireless industry and graduate students specializing in wireless communications. Professionals in wireless service and device manufacturing industries will find the book to be a clear, up-to-date overview of the topic. Readers will benefit from a basic, undergraduate-level understanding of networks and communications. Course instructors can access lecture materials at the companion website:(www.wiley.com/go/bglee)