The Orthogonal Frequency Division Multiplexing (OFDM). Introduction and explanation of five different types of techniques

The Orthogonal Frequency Division Multiplexing (OFDM). Introduction and explanation of five different types of techniques

Author: Dr. Lokesh Chikkananjaiah

Publisher: GRIN Verlag

Published: 2021-02-25

Total Pages: 124

ISBN-13: 3346352757

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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.


Orthogonal Frequency Division Multiplexing for Wireless Communications

Orthogonal Frequency Division Multiplexing for Wireless Communications

Author: Ye Geoffrey Li

Publisher: Springer Science & Business Media

Published: 2006-05-31

Total Pages: 314

ISBN-13: 0387302352

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Orthogonal Frequency Division Multiplexing for Wireless Communications is an edited volume with contributions by leading authorities in the subject of OFDM. Its coverage consists of principles, important wireless topics (e.g. Synchronization, channel estimation, etc.) and techniques. Included is information for advancing wireless communication in a multipath environment with an emphasis on implementation of OFDM in base stations. Orthogonal Frequency Division Multiplexing for Wireless Communications provides a comprehensive introduction of the theory and practice of OFDM. To facilitate the readers, extensive subject indices and references are given at the end of the book. Even though each chapter is written by different experts, symbols and notations in all chapters of the book are consistent.


OFDM Systems for Wireless Communications

OFDM Systems for Wireless Communications

Author: Adarsh Narasimhamurthy

Publisher: Springer Nature

Published: 2022-06-01

Total Pages: 68

ISBN-13: 3031015134

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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


Orthogonal Frequency Division Multiple Access Fundamentals and Applications

Orthogonal Frequency Division Multiple Access Fundamentals and Applications

Author: Tao Jiang

Publisher: CRC Press

Published: 2010-04-21

Total Pages: 640

ISBN-13: 1420088254

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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


OFDM Systems for Wireless Communications

OFDM Systems for Wireless Communications

Author: Adarsh B. Narasimhamurthy

Publisher: Morgan & Claypool Publishers

Published: 2010

Total Pages: 79

ISBN-13: 1598297015

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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


Multi-Carrier Digital Communications

Multi-Carrier Digital Communications

Author: Ahmad R.S. Bahai

Publisher: Springer Science & Business Media

Published: 2006-04-11

Total Pages: 224

ISBN-13: 030646974X

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Multi-carrier modulation, in particular orthogonal frequency division multiplexing (OFDM), has been successfully applied to a wide variety of digital communications applications for several years. Although OFDM has been chosen as the physical layer standard for a diversity of important systems, the theory, algorithms, and implementation techniques remain subjects of current interest. This book is intended to be a concise summary of the present state of the art of the theory and practice of OFDM technology. This book offers a unified presentation of OFDM theory and high speed and wireless applications. In particular, ADSL, wireless LAN, and digital broadcasting technologies are explained. It is hoped that this book will prove valuable both to developers of such systems, and to researchers and graduate students involved in analysis of digital communications, and will remain a valuable summary of the technology, providing an understanding of new advances as well as the present core technology.


Performance Analysis of Orthogonal Frequency Division Multiplexing (OFDM) and Bandwidth Extension Using Carrier Aggregation (CA)

Performance Analysis of Orthogonal Frequency Division Multiplexing (OFDM) and Bandwidth Extension Using Carrier Aggregation (CA)

Author: Sandesh Modhe

Publisher:

Published: 2015

Total Pages: 128

ISBN-13:

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This thesis deals with the performance analysis of an Orthogonal Frequency Division Multiplexing (OFDM) system and the bandwidth extension achieved with carrier aggregation (CA). Data, when transmitted through any communications system, primarily faces three types of problems, errors, power management, and bandwidth. For the purpose of analyzing OFDM performance, we have taken a two-fold approach. Different types of modulation schemes such as QPSK and 16-QAM with OFDM are studied for their Bit Error Rate (BER). A noisy channel adversely affects data transmission. For this work, we study the modulation schemes with OFDM over two types of noise channels, Additive White Gaussian Noise (AWGN) and Rayleigh Fading. BER rates for both these channels are studied comparatively. One of the major drawbacks of using an OFDM communications system is its requirement for high power transmitters due to high Peak to Average Power (PAPR) ratios. In this thesis, we reduce the PAPR by using two distinct algorithms, the Partial Transmit Sequence (PTS) and Selective Mapping Technique (SLM). Performance of the OFDM signal by employing both these algorithms is studied. Furthermore, the last part of this work consists of bandwidth extension by using the technique of carrier aggregation. In this technique, we aggregate two sub-carriers to provide a greater bandwidth. CA is achieved by using two methods, contiguous CA and non-contiguous CA.


Multiplexing

Multiplexing

Author: Somayeh Mohammady

Publisher: BoD – Books on Demand

Published: 2019-09-04

Total Pages: 122

ISBN-13: 1789845688

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Mobile communication has been a critical part of everyday life for the last 30 years. As the demand for wireless communications and higher data rates on these links continues its rapid growth, engineers, scientists, and researchers are required to advance the hardware and software needed to deliver systems for 5G, Massive multiple-input, multiple-output (MIMO), and optical backhaul networks. Now, more than ever before, the fundamental concept of multiplexing is at play. This book is a unique reference for understanding the concept of multiplexing. It provides comprehensive coverage of the practical applications of multiplexing to help the reader better understand its use in these systems. It is a great resource, especially for engineers working on digital signal processing, radio frequency (RF), antenna design, beamforming, and network designs. The book contains chapters on the following topics: • History of multiplexing and how it applies to current technologies; • Different types and applications of multiplexing; • Multiplexing techniques in wireless networks; • Multiple-Input, Multiple-Output Orthogonal Frequency-Division Multiplexing (MIMO-OFD); • Direct-Sequence Optical-Code Division Multiple-Access (DS-OCDMA); • Optically multiplexed systems


OFDM and MC-CDMA for Broadband Multi-User Communications, WLANs and Broadcasting

OFDM and MC-CDMA for Broadband Multi-User Communications, WLANs and Broadcasting

Author: Lajos Hanzo

Publisher: John Wiley & Sons

Published: 2005-01-28

Total Pages: 1014

ISBN-13: 0470861800

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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.