Download or read book Evaluation and Methods to Reduce Co Channel Interference on the Reverse Channel of a CDMA Cellular System written by Adem Durak and published by . This book was released on 1999-03-01 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: With increasing exploitation of information, the demand for mobile access to high data rate multimedia services including high speed internet connection, high quality video/images, teleconferencing, and file transfer continues to grow rapidly for a wide variety of military as well as commercial applications. The current mobile communication systems are narrowband and optimized for voice. They can not support high data rate applications. Simply increasing the bandwidth of existing systems will result in severe degradation due to frequency selective fading, resulting in loss of quality and reliability. It appears that CDMA is the strongest candidate for the third generation mobile communication systems to support these demands. CDMA minimizes the effects of frequency selective fading while reducing the probability of detection and interception by non-authorized users. The primary restriction of the performance of CDMA is the co-channel interference. Since CDMA capacity is only interference limited, the interference reduction equates to better quality of service and greater user capacity. This thesis focuses on analyzing the co-channel interference on the reverse channel of the proposed CDMA cellular systems operating with perfect power control and investigating methods such as sectoring and microzoning in an effort to reduce the interference.
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.
Download or read book Annual Review of Communications Volume 59 written by International Engineering Consortium and published by Intl. Engineering Consortiu. This book was released on 2007 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt: An indispensable reference publication for telecommunication and information-industry professionals. Each year, the IEC brings together into one unique resource the most current thinking and practical experience of industry leaders around the world on a variety of topics facing their areas of specialization. This 700+ page reference tool is a must for executives, managers, engineers, analysts, and educators in all sectors of today's changing information industry.
Download or read book A Comprehensive Review of Methods for the Channel Allocation Problem written by Cheeneebash, Jayrani and published by African Minds. This book was released on 2014-12-01 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of the channel allocation problem has received much attention during the last decade. Several techniques such as genetic algorithm, artificial neural network, simulated annealing, tabu search and others have been used. This book is devoted to compiling all the techniques that have been used to solve the channel allocation problem. Each of the methods is described fully in a manner that explains the essential parts of how the techniques are formulated and applied in solving the problem. This textbook will be helpful to students studying communications or researchers as it compiles all the techniques used since this problem was first solved.
Download or read book Proceedings of International Conference on Information Communications and Signal Processing written by and published by . This book was released on 2003 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Capacity of a Cellular CDMA System Reverse Channel written by Petros Klitorakis and published by . This book was released on 2002-03 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, the reverse channel model for a seven-cell cluster DS-CDMA cellular communications system operating in a slow-flat Nakagami fading and lognormal shadowing environment is developed. The aforementioned system uses imperfect power control to combat the near-far effect and the lognormal shadowing. Forward error correction is applied by using convolutional encoding and soft decision decoding. The probability of bit error is estimated by using a Gaussian approximation, sectoring antennas and a rake receiver at the base station in order to enhance the system's performance. The performance of the system is examined under several values of the standard deviation of lognormal shadowing and the power control error for various numbers of users and values of the Nakagami-m variable by using simulations. Finally, a barrage noise jammer will be introduced and its effect seen in the performance of the cellular communication system for a specific value of E(sub b)/N(sub o).
Download or read book Reverse Link Channel Access Techniques for CDMA Packet Networks written by Subramaniam Alagan Anpalagan and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we propose, analyze and assess three novel radio channel access techniques to effectively manage the interference in the reverse links of a cellular CDMA network with the emphasis on the packet data applications. The first scheme is based on the combined use of rate, power and cell control, whereby base station receivers attempt to operate with equal receive power. In the second approach, the temporal variations of the channels are exploited to schedule packet-transmissions in different modes of operations. The third technique uses the overlapping sectors for adaptive sectoring of a cell based on the non-uniform angular traffic around the base stations. All of these approaches are systematically developed based on the fact that both the interference-reduction and the interference-balancing improve the CDMA system performance. The techniques in effect implement interference control at the system level respectively (a) exploiting the source characteristics of the mobiles for network-wide interference-balancing, (b) time separating the signals based on the relative channel conditions and delaying dominant interferers and (c) jointly selecting the best possible set of antenna based on the angular traffic at the antenna and making the user assignment that minimizes the total transmit power. Algorithms for base station selection, transmission rate adjustment and mobile power adaptation for the above schemes are also discussed. Simulation results and numerical examples that compare ours with previously reported techniques demonstrate the effectiveness of the new techniques.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 2304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ITS Architecture written by and published by . This book was released on 1996 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Principles of Mobile Communication written by Gordon L. Stüber and published by Springer. This book was released on 2017-05-30 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt: This mathematically rigorous overview of physical layer wireless communications is now in a 4th, fully revised and updated edition. The new edition features new content on 4G cellular systems, 5G cellular outlook, bandpass signals and systems, and polarization, among many other topics, in addition to a new chapters on channel assignment techniques. Along with coverage of fundamentals and basic principles sufficient for novice students, the volume includes finer details that satisfy the requirements of graduate students aiming to conduct in-depth research. The book begins with a survey of the field, introducing issues relevant to wireless communications. The book moves on to cover relevant discrete subjects, from radio propagation, to error probability performance, and cellular radio resource management. An appendix provides a tutorial on probability and random processes. The content stresses core principles that are applicable to a broad range of wireless standards. New examples are provided throughout the book to better explain the more complex material to the reader. Additional problems have also been added to those already appearing at the ends of the chapters to make the book more suitable for course instruction.
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.
Download or read book Combined Adaptive Power Rate Control in CDMA Systems written by and published by . This book was released on 2001 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, combined power and rate adaptations in the reverse channel of a multicell CDMA cellular system over a Nakagami-Lognormal frequency selective fading channel are considered. Imperfect power control, user traffic distribution, Intracell interference, co-channel interference, a RAKE receiver and spatial diversity are also considered. Numerical results obtained by Monte Carlo simulation show that power and rate adaptations result in an increase of the system capacity and prolong the mobile station's battery life.
Download or read book Interference Analysis Of and Dynamic Channel Assignment Algorithms In TD CDMA written by Harald Haas and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The radio frequency spectrum for commercial wireless communications has become an expensive commodity. Consequently, radio access techniques are required which enable the efficient exploitation of these resources. This, however, is a difficult task due to an increasing diversity of wireless services. Hence, in order to achieve acceptable spectrum efficiency a flexible air- interface is required. It has been demonstrated that code division multiple access (CDMA) provides flexibility by enabling efficient multi user access in a cellular environment. In addition, time division duplex (TDD) as compared to frequency division duplex (FDD) represents an appropriate method to cater for the asymmetric use of a duplex channel. However, the TDD technique is subject to additional interference mechanisms in particular if neighbouring cells require different rates of asymmetry. If TDD is combined with an interference limited multiple access technique such as CDMA, the additional interference mechanism represents an important issue. This issue poses the question of whether a CDMA/TDD air-interface can be used in a cellular environment. The problems are eased if a hybrid TDMA (time division multiple access) / CDMA interface (TD-CDMA) is used. The reason for this is that the TDMA component adds another degree of freedom which can be utilised to avoid interference. This, however, requires special channel assignment techniques. This thesis analyses cellular CDMA/TDD systems used in indoor environments. A key parameter investigated is the interference in such systems. In the interference analysis a special focus is placed on adjacent channel interference since the jamming entity and victim entity can be in close proximity. The interference analysis shows that co-location of BS's using adjacent channels is not feasible for an adjacent channel protection factor that is less than 40 dB and frame synchronisation errors of more than 10%. Furthermore, it is demonstrated that ideal frame synchronisation does not necessarily yield the highest capacity. As a consequence, a new technique termed 'TS-opposing' is introduced. This method is intended to enable a cellular TD-CDMA/TDD system to apply cell independent channel asymmetry. For this purpose, a centralised DCA is developed. It is found that this algorithm indeed enables neighbouring cells to adopt different rates of asymmetry without a significant capacity loss. Moreover, a decentralised DCA algorithm based on the TS-opposing principle is developed. In this context, a novel TS assignment concept is proposed which reduces the complexity associated with the TS-opposing technique. In addition, the TS assignment plan allows for full spatial coverage. It is shown that the capacity of a TD-CDMA/TDD interface can be greater than the capacity of an equivalent FDD interface. The performance of the decentralised DCA algorithm is limited by the interference in the uplink. Therefore, additional methods which assist in reducing the interference in the uplink are envisaged to further improve the performance of the decentralised DCA algorithm. The exploitation of the TS-opposing technique in two different ways demonstrates that this method can be used to improve the performance of a TD-CDMA/TDD system significantly.
Download or read book Wireless Communication written by Anand Rishabh and published by S. Chand Publishing. This book was released on 2012 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction To Wireless Communication System | Modern Wireless Communication System | Mobile Radio Propogation | Spread Spectrum Modulation Techniques | Equalization And Diversity Techniques | Speech Coding And Quantization Techniques Multiple Access Techniques For Wireless Communication | The Cellular Concept System Design Fundamentals | Wireless Networking | Wireless Systems And Standards | Satellite Communication | Modulation Techniques For Mobile Radio | Architecture And Applications Of Wirless Networks | Appendices | Model Question Papers
Download or read book Co channel Interference Reduction on Cellular Mobile Communication written by Md. Ahmodullah Sarkar and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Co channel Interference Cancellation for DS SS CDMA Mobile Communication System written by Kamel Mostafa Shaheen and published by . This book was released on 1997 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:
