Icc 93 Geneva

This volume contains the proceedings of the Second International Workshop on Advanced Teleservices and High-Speed Communication Architectures (IWACA '94), held in Heidelberg, Germany in September 1994. The IWACA Workshop is a platform for the exchange among researchers and developers from both the multimedia applications and the high-speed telecommunication communities. The book presents revised versions of the 36 papers accepted for presentation at the workshop. They cover several aspects of multimedia applications and asynchronous transfer mode (ATM), and focus on ATM-LANs and ATM for the wide area high-performance network of the future.

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.

Coding theory, system theory, and symbolic dynamics have much in common. A major new theme in this area of research is that of codes and systems based on graphical models. This volume contains survey and research articles from leading researchers at the interface of these subjects.

The primary endeavor of this book is to provide an insight to the Forward Error Correction schemes so as to transfer the extracted features of the detected objects along with any intended data in a reliable manner through underwater channel. The main challenge with respect to the development of the coding techniques is the phenomena governing the propagation of signals through the underwater channel. It offers the biggest challenge imposing severe limitations on the effective throughput of transmission. The major problems encountered in the underwater channel are related to time-varying ISI and frequency-selective fading. An extensive literature review has also been presented with respect to Error Correction Coding schemes. This survey provided the necessary base for formulating the design alternatives. These alternatives attempted to exploit the recent advances in the error correction coding techniques, for data communication through underwater channel. Factors like design and implementation complexity of error correction schemes and the amount of overheads involved in transmission have also been considered in the critical assessment of these alternatives. An overview of the Sonar theory has also been presented along with the brief introduction of the forward-looking Sonars. The types of Forward-Looking Sonars have also been discussed in very brief. A comparison of the general parameters of the terrestrial and underwater systems is also carried out along with the variations in the path loss offered by the two systems with frequency and distance. The characteristics of propagation in the underwater medium are also elaborated. Underwater Channel modeling is also introduced in the book along with a study of the Rician and Rayleigh models which characterize the fading environment. The Rician and Rayleigh distributions are compared in terms of their application to real world scenarios. In the real underwater scenario, there is also a direct path along with the diffused/ indirect paths. Therefore, the most suitable model that can be used for testing the designed coding schemes is the Rician Fading model (K-factor = 2) along with the Additive White Gaussian Noise. The various Forward Error Correction Schemes have been discussed for the purpose of achieving reliable transmission of the formulated data block. The designs of the two Convolutional coding schemes i.e. rate 1/n and rate n/(n+1) have also been presented. It is observed from the comparison of Convolutional and TCM coding schemes that improvement in the performance of either code can be obtained with increase in the coding rate. The Turbo Codes have also been introduced and it will be seen that the performance of turbo code is sensitive to its code structure. The problem of the application of turbo codes to underwater communication systems has also been addressed. The main disadvantage of the Turbo codes is their long latency due to their relatively large codewords and iterative decoding process. However, the Turbo codes score over the Convolutional and the TCM codes in that they can be made sufficiently random to achieve a given BER and by using iterative methods, can be efficiently and feasibly decoded. The designed coding algorithm has been incorporated into the various configurations of the Turbo coding scheme. The variation in the configurations is in the coding rate and the number of states. The interleaver used in the design has been chosen as the random interleaver. The Turbo Coding Schemes have been designed by implementing the Convolutional coders as the constituent encoders using the proposed design rules. The design has been carried out for the 1/n and the n/(n+1) code rates with various states. The performance analysis of the proposed turbo schemes is also presented in terms of the Bit Error Rate (BER) achieved.

This book gives a review of the principles, methods and techniques of important and emerging research topics and technologies in Channel Coding, including theory, algorithms, and applications. Edited by leading people in the field who, through their reputation, have been able to commission experts to write on a particular topic. With this reference source you will: Quickly grasp a new area of research Understand the underlying principles of a topic and its applications Ascertain how a topic relates to other areas and learn of the research issues yet to be resolved Quick tutorial reviews of important and emerging topics of research in Channel Coding Presents core principles in Channel Coding theory and shows their applications Reference content on core principles, technologies, algorithms and applications Comprehensive references to journal articles and other literature on which to build further, more specific and detailed knowledge

This book provides a comprehensive overview of the subject of channel coding. It starts with a description of information theory, focusing on the quantitative measurement of information and introducing two fundamental theorems on source and channel coding. The basics of channel coding in two chapters, block codes and convolutional codes, are then discussed, and for these the authors introduce weighted input and output decoding algorithms and recursive systematic convolutional codes, which are used in the rest of the book. Trellis coded modulations, which have their primary applications in high spectral efficiency transmissions, are then covered, before the discussion moves on to an advanced coding technique called turbocoding. These codes, invented in the 1990s by C. Berrou and A. Glavieux, show exceptional performance. The differences between convolutional turbocodes and block turbocodes are outlined, and for each family, the authors present the coding and decoding techniques, together with their performances. The book concludes with a chapter on the implementation of turbocodes in circuits. As such, anyone involved in the areas of channel coding and error correcting coding will find this book to be of invaluable assistance.