Download or read book Spectral Efficiency Improvement of Low Peak to average Power Ratio Complete Complementary Code Division Multiple Access Systems written by Hendrik de Lange and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation into the peak-to-average power ratio (PAPR) performance of cyclic rotation complete complementary code division multiple access (CR-CC-CDMA) has been conducted. Additionally, a novel orthogonal signalling technique, referred to as complementary rotation keying (CRK), has been developed for improving the spectral efficiency (SE) of CC-CDMA whilst maintaining a low PAPR. The CRK system is based on the concept of CR of CC codes in order to allow interoperability with CR-CC-CDMA systems. To this end, both systems employ a similar transmitter and receiver structure. The CR-CC-CDMA technique suffers from increased PAPR as SE per user is increased. The CRK system offers an improvement in SE, while maintaining the PAPR of a CC-CDMA system. The bit error rates of both systems were unaffected in a joint system, indicating complete interoperability. This allows dynamic adjustment of the PAPR and SE of any user in the system, with users being able to switch between both systems without causing multi user interference.

Download or read book Multi Carrier and Spread Spectrum Systems written by K. Fazel and published by John Wiley & Sons. This book was released on 2004-02-06 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frequency spectrum is a limited and valuable resource for wireless communications. A good example can be observed among network operators in Europe for the prices to pay for UMTS-frequency bands. Therefore, the first goal when designing future wireless communication systems (e.g. 4G - fourth generation) has to be the increase in spectral efficiency. The development in digital communications in the past years has enabled efficient modulation and coding techniques for robust and spectral efficient data, speech, audio and video transmission. These are the multi-carrier modulation (e.g. OFDM) and the spread spectrum technique (e.g. DS-CDMA), where OFDM was chosen for broadcast applications (DVB, DAB) as well as for broadband wireless indoor standards (ETSI HIPERLAN-II, IEEE-802.11) and the DS-CDMA was selected in mobile communications (IS-95, third generation mobile radio systems world wide, UMTS/IMT 2000). Since 1993 various combinations of multi-carrier (MC) modulation and the spread spectrum (SS) technique have been introduced and the field of MC-SS communications has become an independent and important research topic with increasing activities. New application fields have been proposed such as high rate cellular mobile, high rate wireless indoor and LMDS. It has been shown that MC-SS offers the high spectral efficiency, robustness and flexibility that is required for the next generation systems. Meanwhile, different alternative hybrid schemes such as OFDM/OFDMA, MC-TDMA, etc. have been deeply analysed and adopted in different international standards (ETSI-BRAN, IEEE-802 & MMAC). Multi-Carrier & Spread-Spectrum: Analysis of Hybrid Air Interfaces draws together all of the above mentioned hybrid schemes therefore providing a greatly needed resource for system engineers, telecommunication designers and researchers in order to enable them to develop, build and deploy several schemes based on MC-transmission for the next generation systems (which will be an integration of broadband multimedia services covering both 4G mobile and fixed wireless systems). * Offers a complete treatment of multi-carrier, spread-spectrum (SS) and time division multiplexing (TDM) techniques * Provides an in-depth insight into hybrid multiple access techniques based on multi-carrier (MC) transmission * Presents numerous hybrid multiple access and air interface architectures including OFDM/CDMA, MC-CDMA, MC-DS-CDMA and MT-CDMA * Covers new techniques such as space-time coding and software radio Telecommunications engineers, hardware & software system designers and researchers as well as students, lecturers and technicians will all find this an invaluable addition to their bookshelf.

Download or read book Peak to Average Power Ratio Reduction in Orthogonal Frequency Division Multiplexing Systems Using Complementary Codes written by Brendan Michael Hill and published by . This book was released on 2005 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimized Framework for Reduction of Peak to Average Power Ratio in Orthogonal Frequency Division Multiplexing System by Weighted Approach written by Suma Manasa Ponnamaneni and published by . This book was released on 2015 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In the 21st century the role of wireless communications has increased tremendously, especially mobile communication and high speed internet usage. Orthogonal Frequency Division Multiplexing (OFDM) communication technique has far more advantages over traditional communication techniques in terms of data rate, spectral efficiency and low fading. However, it still has a few drawbacks like Peak to Average Power Ratio (PAPR) which causes distortion at the transmitter part of the OFDM. The weighted OFDM approach has been proposed to reduce the PAPR without distortion and successfully remove the respective weight at the receiver end. The proposed method mainly intends to impose some weight on each discrete OFDM signal with certain amount of band limited signal and finally a weighted discrete OFDM signal is formed before it is given to High Power Amplifier (HPA). At the receiver end the same original signal should be received completely but the only condition in this approach is that the time taken at both transmitter and receiver end should be the same. Finally the efficiency and the performance of the proposed weighted scheme are evaluated by the simulation results. The numerical analysis acquired from the proposed weighted scheme reveals that the PAPR of weighted technique is lesser than the conventional clipping and filtering (CF) method and the Bit Error Rate (BER) performance also improved a lot when compared to the CF method.

Download or read book A Simple and Effective Peak to average Power Ratio Reduction Approach Based on Iterative Companding Transform and Filtering Framework of Orthogonal Frequency Division Multiplexing Signal written by Thenappan T. Thiagarajan and published by . This book was released on 2017 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The peak-to-average power ratio (PAPR) reduction in OFDM is an unresolved issue. Intense research has been carried out to solve the issue of peak power and to reduce the impact on overall system performance. PAPR can negatively affect system performance by inducing spectral regrowth and degrading detection efficiency. The purpose of this study is to show how the iterative companding transform and filtering (ICTF) framework can solve the PAPR issue in a redefined way. ICTF is able to obtain low out-of-band interference (OBI) and improved bit error rate (BER) while reducing PAPR significantly. Simulation results show good performance, low complexity, and reliable efficiency over traditional state of methods such as the iterative clipping and filtering technique.

Download or read book Orthogonal Frequency Division Multiple Access Fundamentals and Applications written by Tao Jiang and published by CRC Press. This book was released on 2010-04-21 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supported by the expert-level advice of pioneering researchers, Orthogonal Frequency Division Multiple Access Fundamentals and Applications provides a comprehensive and accessible introduction to the foundations and applications of one of the most promising access technologies for current and future wireless networks. It includes authoritative cove

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2004 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optical Code Division Multiple Access written by Paul R. Prucnal and published by CRC Press. This book was released on 2018-10-03 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Code-division multiple access (CDMA) technology has been widely adopted in cell phones. Its astonishing success has led many to evaluate the promise of this technology for optical networks. This field has come to be known as Optical CDMA (OCDMA). Surveying the field from its infancy to the current state, Optical Code Division Multiple Access: Fundamentals and Applications offers the first comprehensive treatment of OCDMA from technology to systems. The book opens with a historical perspective, demonstrating the growth and development of the technologies that would eventually evolve into today's optical networks. Building on this background, the discussion moves to coherent and incoherent optical CDMA coding techniques and performance analysis of these codes in fiber optic transmission systems. Individual chapters provide detailed examinations of fiber Bragg grating (FBG) technology including theory, design, and applications; coherent OCDMA systems; and incoherent OCDMA systems. Turning to implementation, the book includes hybrid multiplexing techniques along with system examples and conversion techniques to connect networks that use different multiplexing platforms, state-of-the-art integration technologies, OCDMA network security issues, and OCDMA network architectures and applications, including a look at possible future directions. Featuring contributions from a team of international experts led by a pioneer in optical technology, Optical Code Division Multiple Access: Fundamentals and Applications places the concepts, techniques, and technologies in clear focus for anyone working to build next-generation optical networks.

Download or read book Bit Loading and Peak Average Power Reduction Techniques for Adaptive Orthogonal Frequency Division Multiplexing Systems written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In a frequency-selective channel a large number of resolvable multipaths are present which lead to the fading of the signal. Orthogonal frequency division multiplexing (OFDM) is well-known to be effective against multipath distortion. It is a multicarrier communication scheme, in which the bandwidth of the channel is divided into subcarriers and data symbols are modulated and transmitted on each subcarrier simultaneously. By inserting guard time that is longer than the delay spread of the channel, an OFDM system is able to mitigate intersymbol interference (ISI). Significant improvement in performance is achieved by adaptively loading the bits on the subcarriers based on the channel state information from the receiver. Imperfect channel state information (CSI) arises from noise at the receiver and also due to the time delay in providing the information to the transmitter for the next data transmission. This thesis presents an investigation into the different adaptive techniques for loading the data bits on the subcarriers. The choice of the loading technique is application specific. The spectral efficiency and the bit error rate (BER) performance of adaptive OFDM as well as the implementation complexity of the different loading algorithms is studied by varying any one of the parameters, data rate or BER or total transmit power subject to the constraints on the other two. A novel bit loading algorithm based on comparing the SNR with the threshold in order to minimize the BER is proposed and its performance for different data rates is plotted. Finally, this thesis presents a method for reducing the large peak to average power ratio (PAPR) problem with OFDM which arises when the sinusoidal signals of the subcarriers add constructively. The clipping and the probabilistic approaches were studied. The probabilistic technique shows comparatively better BER performance as well as reduced PAPR ratio but is more complex to implement.

Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2003 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals of Wireless Communication written by David Tse and published by Cambridge University Press. This book was released on 2005-05-26 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook takes a unified view of the fundamentals of wireless communication and explains cutting-edge concepts in a simple and intuitive way. An abundant supply of exercises make it ideal for graduate courses in electrical and computer engineering and it will also be of great interest to practising engineers.

Download or read book Understanding LTE with MATLAB written by Houman Zarrinkoub and published by John Wiley & Sons. This book was released on 2014-01-28 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to technical details related to the Physical Layer of the LTE standard with MATLAB® The LTE (Long Term Evolution) and LTE-Advanced are among the latest mobile communications standards, designed to realize the dream of a truly global, fast, all-IP-based, secure broadband mobile access technology. This book examines the Physical Layer (PHY) of the LTE standards by incorporating three conceptual elements: an overview of the theory behind key enabling technologies; a concise discussion regarding standard specifications; and the MATLAB® algorithms needed to simulate the standard. The use of MATLAB®, a widely used technical computing language, is one of the distinguishing features of this book. Through a series of MATLAB® programs, the author explores each of the enabling technologies, pedagogically synthesizes an LTE PHY system model, and evaluates system performance at each stage. Following this step-by-step process, readers will achieve deeper understanding of LTE concepts and specifications through simulations. Key Features: • Accessible, intuitive, and progressive; one of the few books to focus primarily on the modeling, simulation, and implementation of the LTE PHY standard • Includes case studies and testbenches in MATLAB®, which build knowledge gradually and incrementally until a functional specification for the LTE PHY is attained • Accompanying Web site includes all MATLAB® programs, together with PowerPoint slides and other illustrative examples Dr Houman Zarrinkoub has served as a development manager and now as a senior product manager with MathWorks, based in Massachusetts, USA. Within his 12 years at MathWorks, he has been responsible for multiple signal processing and communications software tools. Prior to MathWorks, he was a research scientist in the Wireless Group at Nortel Networks, where he contributed to multiple standardization projects for 3G mobile technologies. He has been awarded multiple patents on topics related to computer simulations. He holds a BSc degree in Electrical Engineering from McGill University and MSc and PhD degrees in Telecommunications from the Institut Nationale de la Recherche Scientifique, in Canada. www.wiley.com/go/zarrinkoub

Download or read book Cognitive Radio Networks written by Yang Xiao and published by CRC Press. This book was released on 2008-12-24 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fueled by ongoing and increasing consumer demand, the explosive growth in spectrum-based communications continues to tax the finite resources of the available spectrum. One possible solution, Cognitive Radio Network (CRN), allows unlicensed users opportunistic access to licensed bands without interfering with existing users. Although some initial s

Download or read book On Spectrally Bounded Codes for Multicarrier Communications written by Kai-Uwe Schmidt and published by Jörg Vogt Verlag. This book was released on 2007 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Parallel Acquisition in Code Division Multiple Access Spread Spectrum Systems written by Roland Reinhard Rick and published by . This book was released on 1995 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Power Efficiency and Diversity Issues for Peak Power Constrained Wireless Communications written by Qijia Liu and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Along with the rapidly increasing demand for high data rate communications, orthogonal frequency division multiplexing (OFDM) has become a popular modulation in current and future communication standards. By distributing a high-speed data stream to many parallel low-rate data streams, OFDM is able to mitigate the detrimental effects of multipath fading using simple one-tap equalizers and achieve high spectral efficiency. However, the OFDM signal waveform suffers from large envelop variations, which are usually measured by the peak-to-average power ratio (PAR). In wireless transmitters, many RF components, especially the power amplifiers, are inherently nonlinear and peak power constrained. Therefore, low power efficiency and/or severe nonlinear distortions are the main shortcomings of OFDM systems.

Download or read book Key Technologies for 5G Wireless Systems written by Vincent W. S. Wong and published by Cambridge University Press. This book was released on 2017-03-02 with total page 527 pages. Available in PDF, EPUB and Kindle. Book excerpt: Get up to speed with the protocols, network architectures and techniques for 5G wireless networks with this comprehensive guide.