Download or read book Statistical Analysis and Reduction of Multiple Access Interference in MC CDMA Systems written by Xuan Li and published by . This book was released on 2008 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Statistical Modelling and Reduction of Multiple Access Interference Power in Wideband DS CDMA and MC CDMA Communications Systems written by Daniel Jeffrey Carey and published by . This book was released on 2006 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most standardisation bodies have based their 3G cellular systems on DS-CDMA (W-CDMA, UMTS, cdma2000). With 4G systems desiring improved services and quality of service standards, this thesis investigates multicarrier CDMA (MC-CDMA) as a genuine air interface candidate. A statistical model of the total MAI power incurred over the uplink channel is shown to be very accurately characterised by the Nakagami-m distribution for both asynchronous DS-CDMA and MC-CDMA techniques. Two new CDMA schemes, DF/DS-CDMA and DF/MC-CDMA, are proposed based on the dual-frequency (DF) switching technique introduced in this thesis. These proposed DF schemes offer substantial MAI reduction upon asynchronous reception and clearly outperform (MAI & BER) the standard DS-CDMA and MC-CDMA systems, however, additional bandwidth is required.

Download or read book Techniques to Reduce Multiple access Interference in Multi carrier CDMA Systems written by Sivapathasundaram Sureshkumar and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Techniques to Reduce Multiple access Interference in Multi carrier CDMA Systems written by Sivapathasundaram Sureshkumar and published by . This book was released on 2006 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 ICI Reduction Methods for MC CDMA Systems written by Meng Wu and published by . This book was released on 2008 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-carrier code-division multiple-access (MC-CDMA) is an important multiple access candidate for 4G wireless communication system. While MC-CDMA provides high performance and high capacity in frequency selective fading channels, it is very sensitive to the signal distortion, especially the Inter Carrier Interference (ICI). We apply self-cancelation and a frequency transmission paradigm to MC-CDMA system to improve the sytem performance in an ICI rich environment. Furthermore, we combine the frequency transmission paradigm FD-MC-CDMA with ICI cancelation. Also, we apply all these three schemes into non-contiguous OFDM and non-contiguous MC-CDMA systems in simple Cognitive Radio communication environments and present the simulation results. Theoretical analysis and numerical results confirm the effectiveness of our proposed new schemes.

Download or read book Frequency Domain Multiuser Detection for CDMA Systems written by Paulo Silva and published by CRC Press. This book was released on 2022-09-01 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 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 Reducing Multiple Access Interference MAI in DS CDMA System written by Banisrekha Mohd Nawi and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Analysis of MC CDMA and CI MC CDMA Using Interference Cancellation Techniques written by Anshul Sharma and published by . This book was released on 2008 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Efficient use of the spectrum is an essential problem in creating any multi-user cellular mobile system. The bandwidth requirements of the future 4G systems far exceed what the existing traditional setup can provide. A more creative utilization of the available bandwidth is more important now than ever before. Improved receiver design that utilizes the frequency and code diversity of the MC-CDMA schemes is one way of increasing the number of users supported at very high bitrates. We discuss the MC-CDMA system operating over a frequency selective, slowly fading channel. We study in detail multiuser Parallel Interference Cancellation detectors employing the MRC and MMSE detectors. Various configurations of the PIC are studied and simulated to evaluate and understand the comparative advantages and disadvantages. In this thesis we offer a review of the literature available on MC-CDMA and CI/MC-CDMA systems. We study the performance of the MRC-PIC-MMSE system both semi-analytically and by computer simulations. By means of computer simulations, we also compare the advantages of using the Carrier Interferometry codes over the Walsh Hadammard codes under various system configurations.

Download or read book Computer Networks and Intelligent Computing written by K. R. Venugopal and published by Springer Science & Business Media. This book was released on 2011-07-20 with total page 701 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 5th International Conference on Information Processing, ICIP 2011, held in Bangalore, India, in August 2011. The 86 revised full papers presented were carefully reviewed and selected from 514 submissions. The papers are organized in topical sections on data mining; Web mining; artificial intelligence; soft computing; software engineering; computer communication networks; wireless networks; distributed systems and storage networks; signal processing; image processing and pattern recognition.

Download or read book Multi Carrier Spread Spectrum written by Khaled Fazel and published by Springer Science & Business Media. This book was released on 2006-02-23 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: The benefits and success of multi-carrier (MC) modulation on one side and the flexibility offered by the spread spectrum (SS) technique on the other side have motivated many researchers to investigate the combination of both techniques since 1993. This combination known as multi-carrier spread spectrum (MC-SS) benefits from the advantages of both systems and offers high flexibility, high spectral efficiency, simple detection strategies, narrow-band interference rejection capability, etc. The basic principle of this combination is straightforward: The spreading is performed as direct sequence spread spectrum (DS-SS) but instead of transmitting the chips over a single carrier, several sub-carriers are employed. The MC modulation and demodulation can easily be realized in the digital domain by performing IFFT and FFT operations. The separation of the users’ signals can be performed in the code domain. MC-SS systems can perform the spreading in frequency direction, which allows for simple signal detection strategies. Since 1993, MC-SS has been deeply studied and new alternative solutions have been proposed. Meanwhile, deep system analysis and comparison with DS-CDMA have been performed that show the superiority of MC-CDMA. The aim of Multi-Carrier Spread-Spectrum is to edit the ensemble of the newest contributions and research results in this new field that have been presented during the 5th International Workshop on Multi-Carrier Spread-Spectrum (MC-SS 2005), held in Oberpfaffenhofen, Germany.

Download or read book Design and Performance Analysis of Multicarrier CDMA Systems written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research being conducted is designed to yield major improvements in the capabilities of military wireless communications systems. The new system is designed around a physical layer based upon a wideband direct sequence (DS) multicarrier (MC) code division multiple access (CDMA) link. Among other things, an MC signal does not require a contiguous spectrum: this means, for example. that an MC CDMA network can be overlaid upon an existing set of narrowband signals simply by leaving appropriate gaps in the placement of the multiple carriers. Such a characteristic will allow the military to employ the same frequencies as used by various commercial systems, thereby making use of the technology advancements in those frequency bands, and yet not be limited in deployment because of excessive interference from conventional narrowband signals. We have emphasized the effect of estimation errors in determining channel state information for use in optimal receiver design for MC CDMA systems, and have performed analyses of performance. as measured by the average probability of error of the system. We have also included the use of space-time spreading.

Download or read book Design and Analysis of Wireless Networks written by Yi Pan and published by Nova Publishers. This book was released on 2005 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary: A compilation of articles that reviews the current design methodology and analytical models of wireless networks.

Download or read book Applied Informatics and Communication Part IV written by Jun Zhang and published by Springer Science & Business Media. This book was released on 2011-08-02 with total page 739 pages. Available in PDF, EPUB and Kindle. Book excerpt: The five volume set CCIS 224-228 constitutes the refereed proceedings of the International conference on Applied Informatics and Communication, ICAIC 2011, held in Xi'an, China in August 2011. The 446 revised papers presented were carefully reviewed and selected from numerous submissions. The papers cover a broad range of topics in computer science and interdisciplinary applications including control, hardware and software systems, neural computing, wireless networks, information systems, and image processing.

Download or read book Evaluation of and Methods to Reduce Co Channel Interference on the Forward Channel of a CDMA Cellular System written by Tanya G. Mayer and published by . This book was released on 1998-12-01 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: The large volumes of information necessary to support today's warfigher require the development of new technology to provide this type of secure, high data rate communication. The flexibility of cellular communications makes it an excellent choice for this purpose. Currently available cellular communications systems are narrowband; that is, they cannot support high data rate applications such as video, full Internet connection, and teleconferencing. Simply increasing the bandwidth of the existing systems will result in severe degradation due to frequency-selective fading, resulting in loss of quality and reliability. Instead, a new wideband cellular system can be used featuring a multicarrier, code division multiple access (CDMA) method. This type of system minimizes the effects of frequency-selective fading while reducing the probability of detection and interception. The limiting factor in this type of system' is co-channel interference. This thesis focuses on analyzing the co- channel interference on the forward channel of the proposed CDMA cellular system and investigating methods such as sectoring and microzoning in an effort to reduce that interference.