Download or read book An Adaptive Multistage Interference Cancellation Receiver for CDMA written by Ashish Kaul and published by . This book was released on 1995 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Multistage Interference Cancellation for DS CDMA System written by Md. Shahidul Islam and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Interference cancellation Receiver for CDMA with MIMO system written by Dr.P.Sreesudha, and published by Archers & Elevators Publishing House. This book was released on with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Adaptive Multi stage Detector for Cancellation of Multiuser Interference in CDMA Wireless Communication Systems written by Nadir Sezgin and published by . This book was released on 1996 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: The classical multiple access techniques such as Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) schemes are band limited in terms of their capacity to be used for mobile radio communication. Recent developments in the area of digital signal processing, makes Code Division Multiple Access (CDMA) as a possible solution to the demand of capacity for the mobile radio communication. The capacity of CDMA is limited by multiuser interference, that is the interference from the other users. The goal of this dissertation is to improve the multiuser CDMA detector with high Bit Error Rate (BER) performance, low complexity, near-fax resistance as well as flexibility to be applied to a wide range of communication channels. We developed an adaptive multi-stage CDMA detector to cancel the multiuser interference. The first-stage of the detector, called decorrelating detector, decorrelates the correlated signals obtained at the match filter bank. The second-stage, called canceller, cancels the multiuser interference exist in the desired signals, using the decorrelated user signals obtained at the decorrelating detector output. The key future of this multi-stage detector is being purely adaptive. The combination of adaptive decorrelating detector and adaptive canceller allows the multi-stage detector achieve near-optimum BER performance and at the same time remain computationally effective. To increse achievable BElT performance an adaptive soft limiter is used at the canceller stage. The underlying structure of this multi-stage detector (i.e. being purely adaptive) allows it to be applied to different channel characteristics. However, throughout this dissertation we use Additive White Gaussian Noise (AWG N) channel for simplicity. To address some of the potential problems that may arise in practice, the adaptive decorrelating detector is tested using computer simulation and in-depth analysis of the problem. If necessary, an alternative solution that do not change the main characteristics of the detector (such as adaptivity and simplicity) is provided. Overall, we conclude that our adaptive detector with its high BER performance and adaptation ability to different channel characteristics, can be considered as an alternative solution to the problem of multiuser interference cancellation in CDMA communication.
Download or read book Interference Cancellation for Short code DS CDMA in the Presence of Channel Fading written by Amit K. Dutta and published by . This book was released on 1997 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interference from other adjacent users in wireless applications is a major problem in direct-sequence code-division multiple-access (DS-CDMA). This is also known as the near-far problem where a strong signal from one user interferes with other users. The current approach to deal with the near-far problem in DS-CDMA systems is to use strict transmitter power control. An alternative approach is to use near-far resistant receivers. The practical near-far resistance receiver structure is the adaptive decorrelating detectors since it avoids complex matrix inversion. The existing CDMA standard known as IS-95 uses a long signature code sequence. However for simplicity, the adaptive multi-user receiver uses short signature code sequence. The problem is that adaptive receivers lose near-far resistance as the number of users increases in the system. This thesis describes a novel method of multistage decision feedback cancellation (DFC) scheme immune from the near-far problem. The performance of the new DFC structure is constructed using three different adaptive algorithms: the least mean squared (LMS), the recursive least squared (RLS) and the linearly constraint constant modulus (LCCM) adaptive algorithms. It is found that LMS adaptive algorithm provides the best result considering its simple hardware complexity. It is also found that the LMS adaptive receiver along with the DFC structure provides a better bit synchronization capability to the over all system. Since the receiver is near-far resistant, the LMS adaptive receiver along with the decision feedback cancellation structure also performs better in the presence of Rayleigh fading.
Download or read book Code Division Multiple Access CDMA written by R. Michael and published by Springer Nature. This book was released on 2022-05-31 with total page 182 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 CDMA Techniques for Third Generation Mobile Systems written by Francis Swarts and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: CDMA Techniques for Third Generation Mobile Systems presents advanced techniques for analyzing and developing third generation mobile telecommunication systems. Coverage includes analysis of CDMA-based systems, multi-user receivers, Turbo coding for mobile radio applications, spatial and temporal processing techniques as well as software radio techniques. Special emphasis has been given to recent advances in coding techniques, smart antenna systems, spatial filtering, and software implementation issues. Internationally recognized specialists contributed to this volume, and each chapter has been reviewed and edited for uniformity. CDMA Techniques for Third Generation Mobile Systems is an invaluable reference work for engineers and researchers involved in the development of specific CDMA systems.
Download or read book Blind Adaptive Multi User Interference Cancellation Detectors and Antenna Array for CDMA Systems written by Dheveegar David Annalingam and published by . This book was released on 2007 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interference Cancelling Receivers with Multiple Antennas for CDMA Systems written by Vafa Ghazi-Moghadam and published by . This book was released on 1997 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multistage Interference Cancellation Techniques in CDMA written by Peng Hui Tan and published by . This book was released on 1999 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Decision feedback Multiuser Detection for DS CDMA Systems written by Min Li and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we propose a modified multistage linear parallel interference cancellation (PIC) structure using the blind adaptive minimum mean-output-energy (MMOE) algorithm for DS-CDMA systems. The proposed receiver has a computational complexity that is linear in the number of users, and exhibits a performance close to the optimum linear minimum mean-squared-error (LMMSE) receiver whose complexity has a cubic dependence on the number of users. Moreover, the proposed blind adaptive MMOE-PIC receiver requires no side information on users' received signal amplitudes, which can further lower the complexity of the overall system. Another multistage detector with low complexity is introduced for DS-CDMA systems over both flat and frequency-selective fading channels. The proposed detector employs the blind adaptive multiuser receiver as the first stage followed by stages with interference cancellation (IC). The performance of the proposed detector is very close to the single user bound and is independent of system loads in flat fading channels. In multipath fading channels, from low to moderate SNR's, the proposed receiver suffers less than 1dB penalty compared with ideal detection without interference. At high SNR's, an error floor occurs for high loaded systems. Finally we consider a class of decision-feedback detectors (DFDs) based on the modified MMSE performance criterion in the presence of dynamic fading. (Abstract shortened by UMI.).
Download or read book Performance Analysis of Linear Multistage Interference Cancellation in Long code CDMA Systems written by Chien-Hwa Hwang and published by . This book was released on 2003 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Multirate CDMA Interference Cancellation Using a Subspace based Approach written by Srinivas Totapally and published by . This book was released on 2005 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Information Theoretic Security written by Kaoru Kurosawa and published by Springer Science & Business Media. This book was released on 2010-09-03 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the thoroughly refereed post-conference proceedings of the 4th International Conference on Information Theoretic Security, held in Shizuoka, Japan, in December 2009. The 13 revised full papers presented together with 6 invited lectures were carefully reviewed and selected from 50 submissions. The papers are organized in topical sections on leakage resilient cryptography, quantum cryptography and indistinguishability, connection to computational security, secret sharing, key agreement from common randomness, random graph and group testing, reliable data transmission and computation, as well as fingerprint and watermarking.
Download or read book Space Time Coding written by Branka Vucetic and published by John Wiley & Sons. This book was released on 2003-06-02 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The capacity of wireless data communications is lagging behind demands due to unsatisfactory performance of the existing wireless networks, such as low data rates, low spectral efficiency and low quality of service. Space-time coding is an effective transmit diversity technique to combat fading in wireless communications. Space-time codes are a highly bandwidth-efficient approach to signalling within wireless communication that takes advantage of the spatial dimension by transmitting a number of data streams using multiple co-located antennas. There are various approaches to the coding structures, including space-time trellis coded modulation, space-time turbo codes and also layered architectures. The central issue in all these various coding structures is the exploitation of multipath effects in order to achieve very high spectral efficiencies. The spectral efficiencies of traditional wireless systems range between 1-5bps/sec/Hz but by using space-time techniques spectral efficiencies of 20-40bps/sec/Hz have been possible. Hence, space-time coding enables an increase in capacity by an order of magnitude. This is the main reason why space-time codes have been included in the standards for the third generation wireless communication systems and ultimately why Space-time Coding will be in great demand by individuals within industry and academia. The comprehensive understanding of space-time coding is essential in the implementation of 3G, and as the only title currently available, Space-Time Coding will be the standard text for Researchers, telecommunication engineers and network planners, academics and undergraduate/postgraduate students, telecommunications managers and consultants.
Download or read book Adaptive Interference Cancellation in DS CDMA written by Dunhua You and published by . This book was released on 1999 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Trickle based Interference Cancellation Schemes for CDMA Systems written by Pooyan Haghighat and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
