Download or read book Performance Analysis of Coded OFDM on Fading Channels with Non ideal Interleaving and Channel Knowledge written by and published by . This book was released on 1996 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance evaluation of channel estimation techniques for LTE downlink system written by Kahsay Meresa and published by Lulu.com. This book was released on 2016-12-03 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis channel estimation techniques for LTE downlink named Least Square, Minimum Mean Square error and Maximum Likelihood estimation techniques are studied for the pilot symbol based channel estimation. In addition to this the performances of these three channel estimation techniques were also studied by introducing averaging, interpolation and hybrid methods.This work also investigates the complexity of the channel estimation techniques in terms of the number of complex multiplications and by varying the FFT size and number of CP(cyclic prefix). furthermore, the effect of varying the number of antennas at the transmitter and receiver ends, where 2 x 2 and 4 x 4 antenna arrangements are considered as a case studies. The performance of these channel estimation techniques is also studied for EVA standard channel model in LTE. The considered channel model is EVA standard channel model with Doppler shift of 300HZ.

Download or read book Single and Multi carrier MIMO Transmission for Broadband Wireless Systems written by Ramjee Prasad and published by River Publishers. This book was released on 2009 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides the basic understanding of the underlying techniques related to PHY-MAC design of future wireless systems. It includes basic concepts related to single- and multi-carrier transmissions together with MIMO techniques.

Download or read book OFDM for Wireless Multimedia Communications written by Richard van Nee and published by Artech House Publishers. This book was released on 2000 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: OFDM for Wireless Multimedia Communications is the first book to take a comprehensive look at OFDM, including a comparison with other forms of single carrier modulation methods. This timely and practical new volume provides the design guidelines you need to maximize benefits from this important new technology.

Download or read book Evaluation of Channel Coding in OFDM Systems written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Channel coding plays a very important role in OFDM systems performance. The structure of OFDM systems makes channel coding more effective in confronting fading channels. Sometimes Coded OFDM is known as COFDM. The role of channel coding in conjunction with frequency and time interleaving is to provide a link between bits transmitted on separated carriers of the signal spectrum, in such a way that the information conveyed by faded carriers can be reconstructed in the receiver. Frequency selectivity, currently known to be a disadvantage, is then turned into an advantage that can be called frequency diversity. Using Channel State Information (CSI), channel coding can yield some additional gain. Channel state information is frequency response of the channel or signal to noise ratio in each carrier. This thesis analyzes OFDM system and the effect of channel coding in reducing BER. Along with this soft decoding and decoding with CSI is also studied. Besides, performance of convolutional codes Turbo codes in OFDM systems is compared and compared. Besides, we compare the performance of convolution and turbo codes in OFDM systems. The results have been validated through simulations. This thesis also presents Space-Frequency Coded OFDM system consisting of two transmitters and a single receiver. Simple Alamouti space time code is used. An Mary PSK modulation is used to modulate the symbols across an OFDM channel. We also proposed a variation of the scheme which tries to spread additional symbols across timefrequency attempting to increase the rate of transmission without changing the type of modulation employed or increasing the bandwidth. A Rayleigh frequency selective slow fading channel is assumed through out the analysis. SER performance of the above systems is carried out with emphasis on the modulation scheme and number of carriers.

Download or read book Journal of Zhejiang University written by and published by . This book was released on 2006 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coded Non Ideal OFDM Systems Analysis and Receiver Designs written by Fei Peng and published by . This book was released on 2007 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents four technical contributions in the theory and practice of low-density parity-check (LDPC) codes and orthogonal frequency division multiplexing (OFDM) systems withtransmission non-linearity and with interference due to high mobility. We first explore the universality of LDPC codes for the binary erasure channel (BEC), the AWGN channel, and the flat Rayleigh fading channel. Using excess mutual information as a performance measure, we demonstrate that an LDPC code designed on a singlechannel can be universally good across the three channels. Thus, a channel for which LDPC code design is simple may be used as a surrogate for channels that are more challenging. Due to fast channel variations, OFDM systems suffer from inter-carrier interference (ICI) in frequency-selective fast fading channels. We propose a novel iterative receiver design that achieves near-optimal performance while maintaining a complexity that grows only linearly with the number of OFDM carriers. Weprove that the matched filter bound for such a channel is also the maximum-likelihood sequence detection (MLSD) bound. Because of the presence of high peaks at OFDM modulator output, amplitude clipping due to amplifier saturation causes performance degradation. We show that existing analyses underestimate the capacity of OFDM systems with clipping, and we analyze thecapacity of clipped OFDM systems with AWGN and frequency-selective Rayleigh fading. We prove that for frequency-selective Rayleigh fading channels, under certain conditions, there exists an SNR threshold, above which the capacity of a clipped system is higherthan that of an unclipped system. We provide upper and lower boundson the channel capacity and closed-form approximations of discrete-input capacities with and without clipping. We also derive tight MLSD lower bounds and propose near-optimal receivers for OFDM systems with clipping. We show that over frequency-selective Rayleigh fading channels, under certain conditions, a clipped system with MLSD can achieve better performance than an unclipped system. We show that the MLSD boundscan be achieved or closely approached by the proposed low complexity receivers in various channel types.

Download or read book Space time Codes and MIMO Systems written by Mohinder Jankiraman and published by Artech House. This book was released on 2004 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation "This resource takes professionals step by step from the basics of MIMO through various coding techniques, to critical topics such as multiplexing and packet transmission. Practical examples are emphasized and mathematics is kept to a minimum, so readers can quickly and thoroughly understand the essentials of MIMO. The book takes a systems view of MIMO technology that helps professionals analyze the benefits and drawbacks of any MIMO system."--BOOK JACKET.Title Summary field provided by Blackwell North America, Inc. All Rights Reserved.

Download or read book Conference Record written by and published by . This book was released on 2003 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wireless Communications written by Giorgio A. Vitetta and published by John Wiley & Sons. This book was released on 2013-03-29 with total page 849 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the theoretical elements at the basis of various classes of algorithms commonly employed in the physical layer (and, in part, in MAC layer) of wireless communications systems. It focuses on single user systems, so ignoring multiple access techniques. Moreover, emphasis is put on single-input single-output (SISO) systems, although some relevant topics about multiple-input multiple-output (MIMO) systems are also illustrated. Comprehensive wireless specific guide to algorithmic techniques Provides a detailed analysis of channel equalization and channel coding for wireless applications Unique conceptual approach focusing in single user systems Covers algebraic decoding, modulation techniques, channel coding and channel equalisation

Download or read book Analysis of Coded OFDM System Over Frequency Selective Fading Channels written by Jun Zheng and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis considers the analysis of system performance and resource allocation for a coded OFDM system over frequency selective fading channels. Due to the inseparable role taken by channel coding in a coded OFDM system, an information theoretical analysis is carried out and taken as the basis for the system performance and throughput. Based on the results of the information theoretical analysis, the optimal system BER performance of a coded OFDM system is first shown to converge to the outage probability for large OFDM block lengths. Instead of evaluating the outage probability numerically, we provide in this thesis a simple analytical closed form approximation of the outage probability for a coded OFDM system over frequency selective quasi-static fading channels. Simulation results of the turbo-coded OFDM systems further confirm the approximation of the outage probability. By taking the instantaneous channel capacity as the analytical building block, system throughput of a coded OFDM system is then provided. With the aim to compare the performance difference between adaptive and uniform resource allocation strategies, the system throughput of different allocation schemes under various channel conditions is analyzed. First, it is demonstrated that adaptive power allocation over OFDM sub-carriers at the transmitter achieves very little gain in terms of throughput over a uniform power distribution scheme. Theoretical analysis is then provided of the throughput increase of adaptive-rate schemes compared with fixed-rate schemes under various situations. Two practical OFDM systems implementing rate-compatible-punctured-turbo-code-based (RCPT-based) hybrid automatic-repeat-request (Hybrid-ARQ) and redundancy incremental Hybrid-ARQ protocols are also provided to verify the analytical results.

Download or read book Performance Analysis of Trellis Codes Transmitted Over Fading Channels written by Chinthananda Tellambura and published by . This book was released on 1993 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Performance of Latency Constrained Turbo like Codes Over Correlated Fading Channels written by Hamid Mahvidi and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of interleaving transmitted symbols over fading channels is investigated. Clarke's model is used to simulate a correlated flat fading channel. The performance of block interleaved convolutional codes is studied in terms of bit and word interleavers and their equivalent super channels. It is shown that a bit interleaved channel can be represented in terms of a super channel of equivalent Doppler spread. Performance of various interleaved convolutional codes is compared to those of non-interleaved turbo-like codes in a correlated fading environment. Simulation results indicate that under stringent delay constraints such as voice communications, interleaved convolutional codes outperform turbo-like codes. However at more relaxed delay constraints of a few thousand bits, non-interleaved turbo-like codes are capable of outperforming convolutional codes.

Download or read book Technologies for the Wireless Future written by Wireless World Research Forum and published by John Wiley & Sons. This book was released on 2005 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: See the future through the vision of the Wireless World Research Forum. Technologies for the Wireless Future, the result of pioneering cooperative work of many academic and industrial researchers from WWRF, provides a wide picture of the research challenges for the future wireless world. Despite much emphasis on hard technology, the user is certainly not forgotten as this book provides an all-encompassing treatment of future wireless technologies ranging from user centred design processes and I-centric communications to end-to-end econfigurability and short-range wireless networks. The content will have a wide-ranging appeal to engineers, researchers, managers and students with interest on future of wireless. "An important publication that highlights the significance of WWRF to the wireless industry. Rarely has one publication covered the whole spectrum of future wireless technologies from human sciences to radio interface technologies, highlighting the research work done both in academic and the business worlds." Tero Ojanperä, Senior Vice President, Head of Nokia Research Center "Provides an excellent overview about the future development of mobile and wireless communication. Starting from a user centric approach and the service infrastructure, a reference model and roadmaps are being built up. This book presents useful and necessary information to all, who are involved in research and development, strategy and standardisation activities towards future systems." Anton Schaaf, CTO and Member of the executive board Siemens COM "The WWRF should be commended for taking an approach that defines technology requirements from a user perspective. This publication makes an important contribution to defining the technologies that will be most relevant to future wireless communications." Padmasree Warrior, Senior Vice President, Chief Technology Officer Motorola

Download or read book Conference Proceedings written by and published by . This book was released on 2004 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: