Download or read book Performance Enhancement of OFDM Using OQAM Modulation written by Riddhi A. Thakkar and published by . This book was released on 2007 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Enhancement of OFDM Systems Using Adaptive Modulation and Coding written by Divya Ravichandran and published by . This book was released on 2007 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Index Modulation for OFDM Communications Systems written by Miaowen Wen and published by Springer Nature. This book was released on 2021-01-04 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thanks to their considerable advantages, index modulation and orthogonal frequency division multiplexing (OFDM) are considered to be promising candidates for future wireless communications. This book focuses on the index modulation techniques for OFDM communications systems, which allow information to be conveyed not only via constellation symbols, but also by the indices of various transmission entities in OFDM systems, such as signal constellations, spreading codes, and pilots. The book discusses representative transmitter and receiver designs, optimization and performance analysis of index modulation based on various transmission entities. It first introduces readers to constellation-based index modulation via a combinatorial approach, including the classical index modulation scheme and two embodiments of information-guided precoding for OFDM systems. It further discusses constellation-based index modulation via a permutational approach, including the basic, generalized, and diversity-enhancing forms. It then describes how the spreading code is used to design an index modulated spread spectrum for OFDM systems, and the extensions to multi-code and multi-user scenarios. In addition it explores information guided pilot insertion for OFDM systems, followed by applications to carrier phase tracking and channel estimation. Lastly, the book highlights a number of open problems and discusses future research directions in the general field of index modulation. Intended for professionals and researchers in the field of wireless communications, this book is also a valuable resource for advanced-level electrical engineering and computer science students.

Download or read book Study and Evaluation of a Frequential Multiplexing Based on OFDM OQAM written by Mohamed Gharba and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is dedicated to the study of the OFDM/OQAM modulation as an alternative to the OFDM modulation. We treat more especially the multi-user environment. In this respect, synchronization aspects are crucial. The different options plus the choice of the waveform are examined in this point of view. Another objective is to precisely show how the OFDM/OQAM can be adapted to a cellular transmission type, taking as reference the 3GPP/LTE system. The main contributions we have made are : 1) Analysis of the desynchronization phenomena : we analyze the effect of desynchronization, according to the time and frequency axes, on the performance of OFDM/OQAM at the receiver side. 2) Synchronization method : we analyze a method of temporal synchronization defined in a single user OFDM/OQAM transmission and we adapt it to a multi-user scenario type. 3) Proposing for a multiple access scheme : we propose a multiple access scheme based on theOFDM/OQAM modulation, alternative to the known techniques OFDMA and SC-FDMA, for the UL transmission in a 3GPP/LTE context.

Download or read book The Orthogonal Frequency Division Multiplexing OFDM Introduction and explanation of five different types of techniques written by Dr. Lokesh Chikkananjaiah and published by GRIN Verlag. This book was released on 2021-02-25 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thesis (M.A.) from the year 2019 in the subject Electrotechnology, grade: 9, , language: English, abstract: The Orthogonal Frequency Division Multiplexing (OFDM) is an important aspect of multicarrier digital data transmission system where a single data stream is transmitted into a several number of lower rates subcarrier signals. In this thesis, there are five different types of the techniques introduced to strengthen the communication quality and capacity. This kind of new standard of transmission of data is the first one to perform with OFDM in data packet based communication system. In wireless communication network, the abstraction of parallel transmission of data symbols is implemented to attain high throughput and effective transmission quality. The OFDM is a method to deal with parallel transmission.

Download or read book Avoiding Effects of OFDM Adjacent Channel Interference by Using Combinations of Modulation Schemes written by Le Tien Anh and published by GRIN Verlag. This book was released on 2009-05 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master's Thesis from the year 2008 in the subject Engineering - Communication Technology, grade: erfolgreich bestanden, Keio University (Graduate school of Science and Technology - School of Science for Open and Environmental Systems), language: English, abstract: Non-orthogonality among adjacent OFDM channels creates OFDM adjacent channel interference and it heavily affects the entire system's performance. Conventional methods to avoid OFDM adjacent channel interference are not only insufficient but also are wasting a lot of frequency resources. In this research, a method using combinations of modulation schemes is proposed to avoid effects of OFDM adjacent channel interference. It can be obtained by modulating the sub-carriers at the outer sides of an OFDM channel with lower order modulation schemes (such as BPSK or QPSK), while modulating the sub-carriers at the inner side of the OFDM channel with higher order modulation schemes (such as 16QAM or 64QAM). Intensive simulations have been carried out to evaluate the performance of the proposed method. The simulation results have shown an increase in the OFDM system's resistance against adjacent channel interference while still maintain the bandwidth efficiency.

Download or read book OFDM and MC CDMA written by Lajos Hanzo and published by John Wiley & Sons. This book was released on 2007-01-11 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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. Currently, a technical in-depth book on this subject is unavailable, which has a similar 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 By providing an all-encompassing self-contained treatment this volume will appeal to a wide readership, as it is both an easy-reading textbook and a high-level research monograph.

Download or read book OFDM Systems for Wireless Communications written by Adarsh Narasimhamurthy and published by Morgan & Claypool Publishers. This book was released on 2010-02-02 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in the standards for digital audio/video broadcasting, WiFi and WiMax. Being a frequency-domain approach to communications, OFDM has important advantages in dealing with the frequency-selective nature of high data rate wireless communication channels. As the needs for operating with higher data rates become more pressing, OFDM systems have emerged as an effective physical-layer solution. This short monograph is intended as a tutorial which highlights the deleterious aspects of the wireless channel and presents why OFDM is a good choice as a modulation that can transmit at high data rates. The system-level approach we shall pursue will also point out the disadvantages of OFDM systems especially in the context of peak to average ratio, and carrier frequency synchronization. Finally, simulation of OFDM systems will be given due prominence. Simple MATLAB programs are provided for bit error rate simulation using a discrete-time OFDM representation. Software is also provided to simulate the effects of inter-block-interference, inter-carrier-interference and signal clipping on the error rate performance. Different components of the OFDM system are described, and detailed implementation notes are provided for the programs. The program can be downloaded here. Table of Contents: Introduction / Modeling Wireless Channels / Baseband OFDM System / Carrier Frequency Offset / Peak to Average Power Ratio / Simulation of the Performance of OFDM Systems / Conclusions

Download or read book Investigation and Analysis of CDMA and OFDM Based Performance Enhancement Techniques in Wireless Communication Systems written by Ahmed Mowafak El Kalagy and published by . This book was released on 2012 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis introduces performance analysis on the effect of using orthogonal polyphase spreading sequences in the uplink scenario of Code Division Multiple Access (CDMA) systems, with the use of two novel dynamic code allocation algorithms to exploit the cross-correlation properties of the spreading sequences. The analysis is also extended to the cooperative communication world, where a cooperative uplink technique is presented that builds on the results and conclusions achieved in the conventional uplink scenario. Theoretical analysis and simulation results are given to highlight the performance gains achieved using the proposed techniques. As Multiple-Input Multiple-Output (MIMO) systems have been increasingly studied and researched in the recent literature to accommodate for the high demand of current and future generations of wireless communications, this thesis follows the same pattern and investigates a new MIMO transmission technique, namely, Spatial Modulation. The thesis then proposes new novel Spatial Modulation enhancement techniques that focus on utilising more of the available system resources for further performance improvements.

Download or read book Performance Analysis and Enhancement of Mobile OFDM Systems written by Mishal Algharabally and published by . This book was released on 2007 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The strength of OFDM is undermined when operating in mobile environments. OFDM is sensitive to Doppler spreading as well as frequency synchronization errors and the orthogonality among the subcarriers of an OFDM symbol can no longer be maintained when the channel is time varying. This dissertation addresses the issue of OFDM systems operating in time varying channels, and investigates the impact of channel time variation on the performance of OFDM systems. A solution to minimize the performance degradation is also presented.

Download or read book Proceedings of the 5th International Conference on Data Science Machine Learning and Applications Volume 1 written by Amit Kumar and published by Springer Nature. This book was released on with total page 1248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book OQAM FBMC for Future Wireless Communications written by Tao Jiang and published by Academic Press. This book was released on 2017-09-13 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: OQAM/FBMC for Future Wireless Communications: Principles, Technologies and Applications introduces the concepts and key technologies of OQAM/FBMC, which has been regarded as the potential physical layer technique in future wireless communication systems. It comprises 10 chapters that provide an overview of wireless communications, introduce wireless channels, single carrier and multicarrier modulations, and three types of FBMC systems, also comparing OQAM/FBMC with OFDM. Other chapters introduce the OQAM/FBMC communication system model, the FFT implementation, CP insertion, PSD analysis, prototype filter optimization, joint PAPR reduction and sidelobe suppression, overhead reduction with virtual symbols, time and frequency domain channel estimations, block-wise SFBC for MIMO OQAM/FBMC, and much more. - Provides a comprehensive guide to most major OQAM/FBMC techniques - Includes a detailed comparison between OFDM and OQAM/FBMC - Provides readers with a complete introduction to OQAM/FBMC, from the transmitter to the receiver - Gives readers an up-to-date view of future mobile communications and how QAM/FBMC supports them

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 Performance Analysis of OFDM in Frequency Selective Slowly Fading Nakagami Channels written by Patrick A. Count and published by . This book was released on 2001-12-01 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: In an effort to offer faster, more reliable wireless communications services to the public, many wireless standardization committees have, in recent years, adopted Orthogonal Frequency Division Multiplexing (OFDM) as the modulation technique of choice. Given the incredible growth in the industry as manifest by the seemingly infinite demand for wireless products and services and the accompanying need for superior performance of these systems in congested and electronically demanding environments, it is evident that OFDM will be at the core of many future high data rate communications systems. This thesis examines the performance of OFDM in frequency-selective slowly fading Nakagami channels. The Nakagami channel is used in this study as it probably best models the propagation characteristics of the environments in which OFDM based systems will be applied.

Download or read book 2020 11th IEEE Annual Information Technology Electronics and Mobile Communication Conference IEMCON written by IEEE Staff and published by . This book was released on 2020-11-04 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: IEMCON 2020 will provide an opportunity for researchers, educators and students to discuss and exchange ideas on issues, trends, and developments in Information Technology, Electronics and Mobile Communication The conference aims to bring together scholars from different disciplinary backgrounds to emphasize dissemination of ongoing research in the fields of Information Technology, Electronics and Mobile Communication The focus of the conference will be on the following areas of research but are not limited to Computer Network Evolutionary Computation and Algorithms Intelligent Information Processing Information System Integration and Decision Support Image Processing and Multimedia Technology VLSI and Microelectronic Circuit Embedded Systems System on Chip (SoC) Design FPGA (Field Programmable Gate Array) Design and Applications

Download or read book Faster than Nyquist Signaling written by Deepak Dasalukunte and published by Springer. This book was released on 2014-07-31 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the challenges and design trade-offs arising during the hardware design of Faster-than-Nyquist (FTN) signaling transceivers. The authors describe how to design for coexistence between the FTN system described and Orthogonal frequency-division multiplexing (OFDM) systems, enabling readers to design FTN specific processing blocks as add-ons to the conventional transceiver chain. • Provides a comprehensive introduction to Faster-than-Nyquist (FTN) signaling transceivers, covering both theory and hardware implementation; • Enables readers to design systems that achieve bandwidth efficiency by making better use of the available spectrum resources; • Describes design techniques to achieve 2x improvement in bandwidth usage with similar performance as that of an OFDM system.

Download or read book Performance Enhancement of the OFDM Based DSRC System Using Frequency Domain MAP Equalization and Soft Output Demappers written by Nabih Jaber and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: