Download or read book Multiuser Detection and Code Timing Estimation for CDMA Systems written by Zhengyu Li and published by . This book was released on 2002 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Code Timing Estimation and Multiuser Detection for CDMA Systems written by Ge Tian Ye and published by . This book was released on 2000 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Channel Estimation and Multiuser Detection Algorithms for Multicarrier mc Cdma Communications Systems written by Hui Cheng and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "New Channel Estimation and Multiuser Detection Algorithms for Multicarrier(MC)-CDMA Communications Systems" by Hui, Cheng, 成慧, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of the thesis entitled New Channel Estimation and Multiuser Detection Algorithms For Multicarrier (MC)-CDMA Communications Systems submitted by Cheng Hui for the degree of Doctor of Philosophy at the University of Hong Kong in September 2005 Multicarrier code division multiple access (MC-CDMA) has been recently proposed as an efficient multicarrier transmission scheme for supporting multiple access communications. However, MC-CDMA is an interference-limited system, which is rather sensitive to multiple access interference (MAI). Multiuser detection techniques are critical to mitigate MAI. Meanwhile, channel estimation is essential to the coherent detection of MC-CDMA signals. This thesis is dedicated to new channel estimation and multiuser detection algorithms for wireless MC-CDMA systems. New blind constrained minimum output energy (CMOE)-based and subspace-based multiuser detection and channel estimation algorithms are first developed. In particular, a new blind CMOE receiver is proposed. The proposed CMOE receiver is based on recursive least square (RLS) updating, and it minimizes the receiver''s output energy while preserving the components of the desired signal. iiiBy imposing quadratic weight constraint, the CMOE detector is made more robust against the channel and correlation matrix estimation errors, and a better performance over the standard CMOE detector is obtained. The steady-state signal-to-interference-plus-noise ratio (SINR) performance of the blind adaptive CMOE and training adaptive minimum mean squared-error (MMSE) detectors is also analyzed. A blind mode decision-directed MMSE detector is then proposed to further improve the performance of the blind CMOE receivers. Simulation results show that the blind mode decision-directed MMSE detector substantially improves the system performance when the frequency-selective channel is slowly varying. Blind and group-blind subspace-based MMSE multiuser detectors are also developed, where the channel coefficients can be blindly estimated. The proposed group-blind multiuser detector considerably outperforms the blind subspace-based method in uplink MC-CDMA channels. It exploits the spreading codes of a group of known users within the cell, while suppressing the unknown interferers from other cells using the MMSE principle. The adaptive implementation of the blind and group-blind multiuser detectors is also studied based on signal and noise subspace tracking algorithms. Numerical simulations show that the convergence of the projection approximation subspace tracking with deflation (PASTd) algorithm is quite slow, while the more complicated bi-iteration square-root singular value decomposition (Bi-SVD) signal subspace tracker presents performance close to the solution with exact singular value decomposition (SVD). MC-CDMA systems are sensitive to narrowband interference (NBI). A new robust channel estimator and a robust multiuser detector are developed to combat time-varying NBI. In particular, an efficient weighted recursive least M-estimate (WRLM) algorithm is proposed to recursively estimate the frequency-selective ivfading channel while providing improved robustness to the time-varying NBI. Furthermore, a weighted least M-estimate (WLM) detector is developed to jointly suppress MAI and time-varying NBI. Simulations show that the proposed robust channel estimator and multiuser d
Download or read book Multiuser Detection in CDMA Mobile Terminals written by Piero Castoldi and published by Artech House. This book was released on 2002 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here's an authoritative, cutting-edge resource that gives you a thorough understanding of CDMA transmission and detection. It offers practical guidance in designing interference-reducing multi-user receivers for mobile radio systems and multi-user adaptive modems for accessing satellite earth stations. The book provides in-depth descriptions of CDMA principles, and of linear and non-linear multi-user detection , and covers the fine details of the realization of a linear multi-user receiver.
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 Multiuser Detection and Channel Estimation for DS CDMA Systems written by Alexander Lampe and published by . This book was released on 2003 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Subspace Multiuser Detection in DS CDMA Communication Systems and Its Applications written by Yong-Suk Moon and published by . This book was released on 1999 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiuser Detection and Channel Estimation for Synchronous CDMA Systems written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiuser Detection and Channel Estimation for DS CDMA Systems written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Space Time Processing for CDMA Mobile Communications written by Pieter van Rooyen and published by Springer Science & Business Media. This book was released on 2005-12-21 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space-Time Processing for CDMA Mobile Communications is one of the first books to: bring together spatial/temporal channel models and analytic performance evaluation techniques; establish a link between smart antenna systems and advanced receiver design techniques; treat smart antennas specifically for UMTS-like communication systems, with applicable simulations and calculations; supply code with Matlab® GUI so readers can run or modify existing simulations or create new ones. The field of smart antenna technology or, more generally, space-time processing is rapidly becoming one of the most promising areas of mobile communications, especially regarding the development of the first practical third-generation mobile communication systems. The authors have addressed many of the most basic questions relating to the use of space-time processing in CDMA-based third-generation systems and have presented models for the integration of space-time processing, error correction coding, and multi-user detection techniques. Included is extensive background information on cellular systems, antenna array theory, smart antenna techniques, performance of basic space-time processors and advanced space-time processors. The book also includes an extensive simulation program written in Matlab®. The simulation code implements both the uplink and the downlink of a UMTS-like communication system. This provides multiple options for simulating system performance using a variety of channel models as well as receiver structures. Space-Time Processing for CDMA Mobile Communications will be an invaluable reference work for engineers and researchers, and a useful source for design engineers enabling them to understand the implications of adding space-time processing systems to CDMA-based communication systems.
Download or read book Estimation of Fading Channel in DS Cdma Multiuser Communications Systems written by Chun-Yu Fung and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Estimation of Fading Channel in DS-CDMA Multiuser Communications Systems" by Chun-yu, Fung, 馮震宇, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of the Thesis Entitled Estimation of Fading Channel in DS-CDMA Multiuser Communications Systems submitted by Fung Chun Yu for the degree of Master of Philosophy at the University of Hong Kong in December 2002 Multipath fading and multiuser access interference are two major impairments in direct-sequence code-division multiple-access (DS-CDMA) systems. Efficient channel estimation and multiuser detection techniques play important roles in overcoming these deficiencies. This thesis is concerned with the design of a space-time (ST) blind adaptive receiver for DS-CDMA systems and the accompanied channel estimation algorithm. A new space-time decorrelating RAKE (ST-DRAKE) receiver is developed for blind reception of CDMA signals in frequency-selective fading channels. It has the advantage that only the knowledge of the desired user's signature waveform is required and therefore no transmission of training sequence is needed. The ST-DRAKE receiver consists of two parts. The first part is a set of constrained adaptive filters that are designed to suppress interference based on the minimum output energy criterion. These filters are implemented in a structure analogous to the general sidelobe canceller in array processing, which is implemented by a multistage Weiner filter is employed to reduce the complexity of the receiver. The second part of the ST-DRAKE receiver coherently combines the outputs of the constrained adaptive filters and gives an estimate of the transmitted signal. Simulation results show that the ST- DRAKE delivers significant performance improvement by exploiting the spatial diversity of the antenna array. The problem of estimating fast fading channels in the proposed receiver is also addressed. The time-varying channel is modeled as an autoregressive process and the Kalman filter is employed to estimate the time-varying channel coefficients. A robust Kalman filter based on the M-estimate cost function is also developed to suppress impulsive noise present in the received signals. Simulation results show that the Kalman filter provides more accurate channel estimate to the ST-DRAKE than using the decomposition method. Simulation results also show that the coupled receiver has a performance comparable to the optimum minimum mean-squared error receiver with known channel information. DOI: 10.5353/th_b2750902 Subjects: Code division multiple access Wireless communication systems
Download or read book Code Division Multiple Access CDMA written by R. Michael Buehrer and published by Morgan & Claypool Publishers. This book was released on 2006 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the basic aspects of Code Division Multiple Access or CDMA. It begins with an introduction to the basic ideas behind fixed and random access systems in order to demonstrate the difference between CDMA and the more widely understood TDMA, FDMA or CSMA. Secondly, a review of basic spread spectrum techniques are presented which are used in CDMA systems including direct sequence, frequency-hopping and time-hopping approaches. The basic concept of CDMA is presented, followed by the four basic principles of CDMA systems that impact their performance: interference averaging, universal frequency reuse, soft handoff, and statistical multiplexing. The focus of the discussion will then shift to applications. The most common application of CDMA currently is cellular systems. A detailed discussion on cellular voice systems based on CDMA, specifically IS-95, is presented. The capacity of such systems will be examined as well as performance enhancement techniques such as coding and spatial filtering. Also discussed are Third Generation CDMA cellular systems and how they differ from Second Generation systems. A second application of CDMA that is covered is spread spectrum packet radio networks. Finally, there is an examination of multi-user detection and interference cancellation and how such techniques impact CDMA networks. This book should be of interest and value to engineers, advanced students, and researchers in communications.
Download or read book Multiuser Detection in CDMA Systems and Methods for Combined Data Detection and Channel Estimation Over Asynchronous CDMA Flat Rayleigh Fading Channels written by David Pham and published by . This book was released on 2003 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book OFDM and MC CDMA for Broadband Multi User Communications WLANs and Broadcasting written by Lajos Hanzo and published by John Wiley & Sons. This book was released on 2005-01-28 with total page 1014 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal frequency-division multiplexing (OFDM) is a method of digital modulation in which a signal is split into several narrowband channels at different frequencies. CDMA is a form of multiplexing, which allows numerous signals to occupy a single transmission channel, optimising the use of available bandwidth. Multiplexing is sending multiple signals or streams of information on a carrier at the same time in the form of a single, complex signal and then recovering the separate signals at the receiving end. Multi-Carrier (MC) CDMA is a combined technique of Direct Sequence (DS) CDMA (Code Division Multiple Access) and OFDM techniques. It applies spreading sequences in the frequency domain. Wireless communications has witnessed a tremendous growth during the past decade and further spectacular enabling technology advances are expected in an effort to render ubiquitous wireless connectivity a reality. This technical in-depth book is unique in its detailed exposure of OFDM, MIMO-OFDM and MC-CDMA. A further attraction of the joint treatment of these topics is that it allows the reader to view their design trade-offs in a comparative context. Divided into three main parts: Part I provides a detailed exposure of OFDM designed for employment in various applications Part II is another design alternative applicable in the context of OFDM systems where the channel quality fluctuations observed are averaged out with the aid of frequency-domain spreading codes, which leads to the concept of MC-CDMA Part III discusses how to employ multiple antennas at the base station for the sake of supporting multiple users in the uplink Portrays the entire body of knowledge currently available on OFDM Provides the first complete treatment of OFDM, MIMO(Multiple Input Multiple Output)-OFDM and MC-CDMA Considers the benefits of channel coding and space time coding in the context of various application examples and features numerous complete system design examples Converts the lessons of Shannon’s information theory into design principles applicable to practical wireless systems Combines the benefits of a textbook with a research monograph where the depth of discussions progressively increase throughout the book This all-encompassing self-contained treatment will appeal to researchers, postgraduate students and academics, practising research and development engineers working for wireless communications and computer networking companies and senior undergraduate students and technical managers.
Download or read book Precoding Techniques for Digital Communication Systems written by C.-C. Kuo and published by Springer Science & Business Media. This book was released on 2008-09-18 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past two decades, many communication techniques have been developed to achieve various goals such as higher data rate, more robust link quality,andmoreusercapacityinmorerigorouschannelconditions.Themost well known are, for instance, CDMA, OFDM, MIMO, multiuser OFDM, and UWB systems.All these systems havetheir ownunique superioritywhile they also induce other drawbacks that limit the system performance. Conventional way to overcome the drawback is to impose most of the computational e?ort in the receiver side and let the transmitter design much simpler than receiver. The fact is that, however, by leveraging reasonable computational e?ort to the transmitter, the receiver design can be greatly simpli?ed. For instance, multiaccess interference (MAI) has long been considered to limit the perf- mance of multiuser systems. Popular solutions to mitigate MAI issue include multiuser detection (MUD) or sophisticated signal processing for interference cancellation such as PIC or SIC. However, those solutions impose great b- den in the receiver. In this case, precoding o?er good solutions to achieve simple transceiver designs as we will mention later in this book. This book is intended to provide a comprehensive review of precoding techniques for digital communications systems from a signal processing p- spective. The variety of selected precoding techniques and their applications makes this book quite di?erent from other texts about precoding techniques in digital communication engineering.
Download or read book Code aided Multiuser Detection in Multiple Access Wireless Communication Systems written by Ping Liu and published by . This book was released on 2004 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiuser Detection written by Sergio Verdú and published by Cambridge University Press. This book was released on 1998-08-13 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally published in 1998, Multiuser Detection provides a comprehensive treatment of the subject of multiuser digital communications.
