Threshold Decoding
The content of these notes is a tentative survey of the results recently obtained concerning one of the most attractive methods known for decoding linear block codes. The material is divided into four sections, each followed by a list of references. The f
- PDF / 25,518,242 Bytes
- 337 Pages / 481.89 x 691.654 pts Page_size
- 101 Downloads / 233 Views
CODING AND COMPLEXITY
EDITED BY
G. LONGO UNIVERSITY OF TRIESTE
PREFACE BY
J.
L. MASSEY
UNIVERSITY OF NOTRE DAME
SPRINGER-VERLAG WIEN GMBH
This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concemed specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machine or similar means, and storage in data banks.
©
1975 by Springer-Verlag Wien
Originally published by Springer-Verlag Wien-New York in 1975
ISBN 978-3-211-81341-6 DOI 10.1007/978-3-7091-3008-7
ISBN 978-3-7091-3008-7 (eBook)
PREFACE
The picturesque northern Italian city of Udine, lying seventy kilometers to the north and west of Trieste, was the setting in July 1974 for a two week summer school on "Coding and Complexity". . This school was held under the auspices of the Centre International des SCiences Mecaniques (CISM) in Udine and was the brainchild of Professor Giuseppe Longo of the University of Trieste, who doubles as a member of the CISM staff It was Longo's intention that this summer school should probe the practicality of the "coding theorems" of information theory. In their original statement by Shannon, these theorems promised arbitrarily reliable communication at any rate less than channel capacity provided that "long enough" codes were used. But how long is "long enough" and how "complex" to instrument are such long codes? To answer these questions in the light of the quarter-century of information-theoretic research since the publication of Shannon's paper, Longo invited as lecturers a number of scholars who have been active in various areas of coding research. This volume is the collection of their written lectures which were in most instances further polished and amplified after the summer school in light of the many stimulating interchanges which followed their oral presentation. The summer school was a lively one that educated listener and lecturer alike. Of the nine contributions in this volume, the first five deal with channel coding, or "error-correcting coding" to use the more common but less precise term. To talk of "correcting errors" already implies that the channel input and output alphabets coincide, something that information theorists have come to recognize is a wasteful feature in some communication situations where "soft decision" demodulation is substantially superior to "hard decision" demodulation. The first contribution, "Error Bounds for Tree Codes, Trellis Codes, and Convolutional Codes with Encoding and Decoding Procedures", is that by this writer who took advantage of the ten lecture hours granted him by Professor Longo to give a rather complete exposition of these non-block forms of coding and to include a number of his previously unpublished results. This paper was written for the reader with no background in convolutional coding and was designed to bring him to the current state of knowledge in this field. The description of encoding procedures and decoding procedures (Viterbi decoding and se
