[PDF] Modulation And Constrained Coding Techniques For Wireless Infrared Communication Channels eBook

Author : Steve Hranilovic
Publisher :
Page : pages
File Size : 43,25 MB
Release : 1999
Category :
ISBN :

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Short-distance, point-to-point wireless infrared optical links provide a cost-effective means of high speed data transfer between portable devices. To investigate such links, a test-bench and circuits were constructed to determine the limitations of existing optoelectronics. The results of these measurements we used to formulate a signal-space channel model which is employed for the subsequent analysis of candidate bandwidth efficient modulation schemes. The modulation scheme Adaptively Biased QAM (AB-QAM) is developed based on the channel model. AB-QAM provides an asymptotic 3 dB optical SNR improvement over PAM while maintaining the same bandwidth efficiency. The use of constellation shaping is shown to further improve the average optical power efficiency of AB-QAM. This thesis proposes the use of constrained coding techniques to satisfy the non-negativity constraint of the optical channel. These coding techniques are illustrated through an example and contrasted to a baseline case. Constrained coding techniques allow greater flexibility in the choice of pulse shapes used in the channel, leading to possible optical power and bandwidth gains.

Author : Evgenii Krouk
Publisher : John Wiley & Sons
Page : 691 pages
File Size : 25,75 MB
Release : 2011-02-21
Category : Technology & Engineering
ISBN : 0470745053

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The high level of technical detail included in standards specifications can make it difficult to find the correlation between the standard specifications and the theoretical results. This book aims to cover both of these elements to give accessible information and support to readers. It explains the current and future trends on communication theory and shows how these developments are implemented in contemporary wireless communication standards. Examining modulation, coding and multiple access techniques, the book is divided into two major sections to cover these functions. The two-stage approach first treats the basics of modulation and coding theory before highlighting how these concepts are defined and implemented in modern wireless communication systems. Part 1 is devoted to the presentation of main L1 procedures and methods including modulation, coding, channel equalization and multiple access techniques. In Part 2, the uses of these procedures and methods in the wide range of wireless communication standards including WLAN, WiMax, WCDMA, HSPA, LTE and cdma2000 are considered. An essential study of the implementation of modulation and coding techniques in modern standards of wireless communication Bridges the gap between the modulation coding theory and the wireless communications standards material Divided into two parts to systematically tackle the topic - the first part develops techniques which are then applied and tailored to real world systems in the second part Covers special aspects of coding theory and how these can be effectively applied to improve the performance of wireless communications systems

Author : Alister Burr
Publisher : Prentice Hall PTR
Page : 392 pages
File Size : 11,36 MB
Release : 2001
Category : Computers
ISBN :

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Preface. Abbreviations. 1. Introduction to modulation and coding. 2. Principles of linear modulation. 3. Modulation for non-linear systems. 4. Modem design. 5. Principles of FEC Coding. 6. Cyclic block codes. 7. Convolutionals codes. 8. Coded modulation. 9. Modulation and coding on multipath channels. 10. OFDM. 11. Turbo-codes. Appendix 1. Finite field theory. Appendix 2. The MAP algorithm.

Author : Ezio Biglieri
Publisher : Springer Science & Business Media
Page : 433 pages
File Size : 20,74 MB
Release : 2006-07-06
Category : Technology & Engineering
ISBN : 1402080840

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Accessible introduction to the theoretical foundations of modern coding theory Including numerous applications to wireless transmission systems The author is famous in the field of coding and wireless communications for his work in the area of faded channels & communcations.

Author :
Publisher :
Page : pages
File Size : 16,36 MB
Release : 2002
Category :
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Because of low-cost optical devices and virtually unlimited bandwidth, optical wireless communications (OWC) for indoor wireless local area networks (WLANs) have recently become an attractive alternative to radio frequency systems. Since optical signals cannot penetrate through walls or other opaque barriers, the security of infrared WLANs is very high and there is no interference between rooms. Subsequently, cell planning is simple and easy, and the potential capacity of an optical-based network in a building is extremely high. However, the system link is susceptible to path loss and multipath dispersion. In addition, the average transmit power is constrained by eye-safety regulations and power consumption concerns. Hence, most recent research deals with the physical layer aspects such as modulation, equalization and error-control coding in order to cope with these draw-backs, especially the effects of multipath dispersion. The objective of this thesis is to study practical signaling techniques capable of eliminating the effects of intersymbol interference (ISI). Regarding the drawbacks of OWC, modulation schemes which are power and band-width efficient are considered. Pulse-position modulation (PPM) has been employed for IrDA and IEEE802.11 standards because it offers high power efficiency. However, it re-quires high bandwidth so that its performance is considerably degraded when the channel is more corrupted by ISI. A number of modified PPM techniques have been proposed to improve bandwidth efficiency. This thesis introduces a hybrid between pulse-amplitude modulation (PAM) and differential pulse-position modulation (DPPM), named differential amplitude pulse-position modulation (DAPPM), in order to gain a better compromise between power and bandwidth efficiency. It yields better bandwidth and/or power efficiency than PAM, PPM and DPPM depending on the number of amplitude levels (A), and the maximum length (L) of a symbol. The channel capacity of PPM, DPPM and DAP.

Author : K. Deergha Rao
Publisher : Springer Nature
Page : 484 pages
File Size : 40,55 MB
Release : 2019-11-22
Category : Mathematics
ISBN : 9811505616

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This book discusses the latest channel coding techniques, MIMO systems, and 5G channel coding evolution. It provides a comprehensive overview of channel coding, covering modern techniques such as turbo codes, low-density parity-check (LDPC) codes, space–time coding, polar codes, LT codes, and Raptor codes as well as the traditional codes such as cyclic codes, BCH, RS codes, and convolutional codes. It also explores MIMO communications, which is an effective method for high-speed or high-reliability wireless communications. It also examines the evolution of 5G channel coding techniques. Each of the 13 chapters features numerous illustrative examples for easy understanding of the coding techniques, and MATLAB-based programs are integrated in the text to enhance readers’ grasp of the underlying theories. Further, PC-based MATLAB m-files for illustrative examples are included for students and researchers involved in advanced and current concepts of coding theory.

Author : Bradley S. Tice
Publisher : CRC Press
Page : 254 pages
File Size : 42,23 MB
Release : 2014-10-27
Category : Mathematics
ISBN : 1466577932

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This new book-the first of its kind-examines the use of algorithmic techniques to compress random and non-random sequential strings found in chains of polymers. The book is an introduction to algorithmic complexity. Examples taken from current research in the polymer sciences are used for compression of like-natured properties as found on a chain o

Author : John L. Fan
Publisher : Springer Science & Business Media
Page : 268 pages
File Size : 15,66 MB
Release : 2012-12-06
Category : Technology & Engineering
ISBN : 1461515254

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Constrained Coding and Soft Iterative Decoding is the first work to combine the issues of constrained coding and soft iterative decoding (e.g., turbo and LDPC codes) from a unified point of view. Since constrained coding is widely used in magnetic and optical storage, it is necessary to use some special techniques (modified concatenation scheme or bit insertion) in order to apply soft iterative decoding. Recent breakthroughs in the design and decoding of error-control codes (ECCs) show significant potential for improving the performance of many communications systems. ECCs such as turbo codes and low-density parity check (LDPC) codes can be represented by graphs and decoded by passing probabilistic (a.k.a. `soft') messages along the edges of the graph. This message-passing algorithm yields powerful decoders whose performance can approach the theoretical limits on capacity. This exposition uses `normal graphs,' introduced by Forney, which extend in a natural manner to block diagram representations of the system and provide a simple unified framework for the decoding of ECCs, constrained codes, and channels with memory. Soft iterative decoding is illustrated by the application of turbo codes and LDPC codes to magnetic recording channels. For magnetic and optical storage, an issue arises in the use of constrained coding, which places restrictions on the sequences that can be transmitted through the channel; the use of constrained coding in combination with soft ECC decoders is addressed by the modified concatenation scheme also known as `reverse concatenation.' Moreover, a soft constraint decoder yields additional coding gain from the redundancy in the constraint, which may be of practical interest in the case of optical storage. In addition, this monograph presents several other research results (including the design of sliding-block lossless compression codes, and the decoding of array codes as LDPC codes). Constrained Coding and Soft Iterative Decoding will prove useful to students, researchers and professional engineers who are interested in understanding this new soft iterative decoding paradigm and applying it in communications and storage systems.