Download or read book Software Implementation of Orthogonal Frequency Division Multiplexing OFDM Scheme for Mobile Radio Channel written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) is a transmission technique which ensures efficient utilization of the spectrum by allowing overlap of carriers. OFDM is a combination of modulation and multiplexing that is used in the transmission of information and data. Compared with the other wireless transmission techniques like Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), OFDM has numerous advantages like high spectral density, its robustness to channel fading, its ability to overcome several radio impairment factors such as effect of AWGN, impulse noise, multipath fading, etc. Due to this it finds wide application in Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB), and Wireless LAN. Most of the wireless LAN standards like IEEE 802.11a or IEEE 802.11g use the OFDM as the main multiplexing scheme for better use of spectrum. In fact in the 4G telecommunication system OFDMA is the backbone of it. This project deals with the software simulation of this OFDM system in a mobile radio channel using the software tools of MATLAB® and SIMULINK®. From this simulation the performance of OFDM system in mobile radio channel is studied. Apart from this we also compare the OFDM system performance with the performance of the DS-CDMA system in the mobile radio channel.

Download or read book OFDM Systems for Wireless Communications written by Adarsh B. Narasimhamurthy and published by Morgan & Claypool Publishers. This book was released on 2010 with total page 79 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 OFDM Systems for Wireless Communications written by Adarsh Narasimhamurthy and published by Springer Nature. This book was released on 2022-06-01 with total page 68 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 Orthogonal Frequency Division Multiplexing for Wireless Communications written by Ye Geoffrey Li and published by Springer Science & Business Media. This book was released on 2006-05-31 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

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 Orthogonal Frequency Division Multiplexing with Diversity for Future Wireless Systems written by Khoa N. Le and published by Bentham Science Publishers. This book was released on 2012 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The book examines several aspects of Orthogonal Frequency Division Multiplexing (OFDM) employing linear diversity techniques such as inter-carrier interference, bit error rate, peak to average power and inter-block interference. It should be a useful refe"

Download or read book OFDM written by Hermann Rohling and published by Springer Science & Business Media. This book was released on 2011-03-22 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Preliminary): The Orthogonal Frequency Division Multiplexing (OFDM) digital transmission technique has several advantages in broadcast and mobile communications applications. The main objective of this book is to give a good insight into these efforts, and provide the reader with a comprehensive overview of the scientific progress which was achieved in the last decade. Besides topics of the physical layer, such as coding, modulation and non-linearities, a special emphasis is put on system aspects and concepts, in particular regarding cellular networks and using multiple antenna techniques. The work extensively addresses challenges of link adaptation, adaptive resource allocation and interference mitigation in such systems. Moreover, the domain of cross-layer design, i.e. the combination of physical layer aspects and issues of higher layers, are considered in detail. These results will facilitate and stimulate further innovation and development in the design of modern communication systems, based on the powerful OFDM transmission technique.

Download or read book Implementation of Channel Estimation Algorithms in OFDM written by Navdeep Bansal and published by LAP Lambert Academic Publishing. This book was released on 2014-11-01 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) is a very potential technique for transmitting high bit rate data over indoor and outdoor wireless communication channels with high bandwidth efficiency and robustness to multipath delay. OFDM is a multichannel modulation that divides a given channel into many parallel sub-channels or subcarriers, so that multiple symbols are sent in parallel. The first multichannel modulation systems appeared in the 1950's as military radio links, best characterized as frequency-division multiplexed systems. The first OFDM schemes were presented by Chang and Saltsburg, in which actual use/ practicability of OFDM was limited. However, later on the OFDM was made more practical through work describe in the article uses Discrete Fourier transform (DFT) with a cyclic prefix. The DFT implemented with a Fast Fourier Transform (FFT)) and the cyclic prefix have made OFDM both practical and attractive to the radio link designer. A similar multichannel modulation scheme, Discrete Multi-Tone (DMT) modulation, has been developed for static channels such as the digital subscriber loop.

Download or read book OFDM Performance in a Mobile Radio Channel written by David T. Harvatin and published by . This book was released on 1996 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Orthogonal Frequency Division Multiplexing OFDM Implementation as Part of a Software Devined Radio SDR Environment written by Christoph Sonntag and published by . This book was released on 2005 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multi Carrier and Spread Spectrum Systems written by Khaled Fazel and published by John Wiley & Sons. This book was released on 2008-09-15 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The technological progress in multi-carrier (MC) modulation led orthogonal frequency division multiplexing (OFDM) to become an important part of beyond 3G cellular mobile communication standards, including LTE and WiMAX. In addition, the flexibility offered by the spread spectrum (SS) and time division multiplexing (TDM) techniques motivated many researchers to investigate several MC combined multiple access schemes, such as MC-CDMA, OFDMA and MC-TDMA. These schemes benefit from the advantages of each sub-system and offer high flexibility, high spectral efficiency, simple detection strategies and narrow-band interference rejection capability. Multi-Carrier and Spread Spectrum Systems is one of the first books to describe and analyze the basic concepts of multi-carrier OFDM transmission and its combination with spread spectrum (MC-CDMA). The different architectures and detection strategies as well as baseband-related transceiver components are explained. This includes topics like FEC channel coding and decoding, modulation and demodulation (IFFT/FFT), digital I/Q-generation, time and frequency synchronisation, channel estimation, frequency domain equalization and RF aspects such as phase noise and non-linearity issues. Concrete examples of its applications for cellular mobile communication systems (B3G/4G) are given. Further derivatives of MC-SS (such as OFDMA, SS-MC-MA and DFT-spread OFDM) and their corresponding applications in the LTE, WiMAX, WLAN and DVB-RCT standards are detailed. Capacity and flexibility enhancements of multi-carrier OFDM systems by different MIMO diversity techniques such as space time/frequency coding (STC, SFC) and software defined radio concepts are also described. Written in a highly accessible manner this book provides a unique reference on the topics of multi-carrier and spread spectrum communications, assisting 4G engineers with their implementation. Fully updated new edition of successful text, including two new chapters on LTE and WiMAX Describes in detail new applications of OFDM in mobile communication standards Examines all multi-carrier spread spectrum schemes, with in-depth analysis, from theory to practice Introduces the essentials of important wireless standards based on multi-carrier/spread spectrum techniques.

Download or read book Study of Efficient Link Adaptation Schemes in Wireless Orthogonal Frequency Division Multiplexing OFDM Systems written by Eun Ho Choi and published by . This book was released on 2009 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless communication systems require high spectral efficiency and throughput in order to be cost-effective. Link adaptation schemes are known to be a good solution to achieve this goal. However, the necessity of additional information or increased complexity prevents these schemes from being implemented. In this context, research on resource allocation based on different constraints, such as complexity or feedback, is important. The major contribution of this dissertation is the development of three novel techniques to enhance performance in practical implementations of the adaptive OFDM systems. This dissertation first introduces a new multiuser OFDM system to enhance performance in the low SNR regime. In this scheme, multiuser diversity can be efficiently amplified from random power allocation and opportunistic scheduling. Higher spectral efficiency can be achieved without an increase of complexity or feedback amount compared to conventional multiuser OFDM systems using equal power allocation. This dissertation also presents a modified multi-mode power loading scheme. A modified multi-mode power loading scheme can circumvent the limit of current multi-mode power loading schemes by significantly reducing search amount from 2N - 1 to N, where N is the number of subcarriers. Finally, this dissertation has introduced adaptive OFDM systems using channel gain order information in limited feedback environments. Adaptive OFDM systems using the order mapping technique achieve comparable performance to conventional adaptive OFDM systems in terms of bit error rate and average spectral efficiency, while the amount of feedback is significantly reduced. Furthermore, by simply exploiting order mapping and interpolation, the analyzing technique circumvents the practical shortcomings of previous limited feedback techniques for OFDM systems.

Download or read book Multi Carrier Digital Communications written by Ahmad R.S. Bahai and published by Springer Science & Business Media. This book was released on 2006-04-11 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

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 Measurement Modeling and OFDM Synchronization for the Wideband Mobile to mobile Channel written by Guillermo Acosta-Marum and published by . This book was released on 2007 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wideband measurements of the mobile-to-mobile channel, especially of the harshest channels, are necessary for proper design and certification testing of mobile-to-mobile communications systems. A complete measurement implies that the Doppler and delay characteristics are measured jointly. However, such measurements have not previously been published.

Download or read book Software Development of an Orthogonal Frequency Division Multiplexing OFDM Transceiver written by Ker Chea Lau and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Implementation of an FPGA based OFDM System written by Joshua Winslow and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) is a widely used technique for the transmission of data in modern wireless communication systems such as 5G. OFDM combines the benefits of a modulation scheme, such as Quadrature Amplitude Modulation (QAM), and Frequency Division Multiplexing (FDM) to increase the robustness and data density of a communication link and reducing the bandwidth required. In this thesis, a configurable OFDM system was modeled and tested using an Intel-Altera Cyclone V FPGA. Field Programmable Gate Arrays (FPGAs) provide flexibility and high performance at parallel processing. They are useful for designing a configurable product and for rapid prototyping of potential ASICs with high-volume applications. The design was created in the Quartus Prime Lite Software and implemented in hardware. This system tested measurably better overall versus other previous FPGA attempts in latency, throughput, and flexibility. A QAM-16 Modulator, 16-point IFFT and FFT, and QAM-16 Demodulator were tested and implemented to send images through a channel. The system, running at 50 MHz, experienced a total, round-trip latency of 3.6[mu]S with a data throughput of 200 Mbps. While running at this clock speed, the power draw from the FPGA was found to be 465mW. For use in testing, a 128x128 image was used to verify the completeness and functionality of the design by using Python to compare the original image to the recovered image from the system. A performance scalability function was derived for the designed platform.