Journal ArticleDOI
The Philosophy of PCM
B.M. Oliver,John R. Pierce,Claude E. Shannon +2 more
- Vol. 36, Iss: 11, pp 1324-1331
TLDR
This paper shows in a general way some of the advantages of PCM, and distinguishes between what can be achieved with PCM and with other broadband systems, such as large-index FM.Abstract:
Recent papers describe experiments in transmitting speech by PCM (pulse code modulation). This paper shows in a general way some of the advantages of PCM, and distinguishes between what can be achieved with PCM and with other broadband systems, such as large-index FM. The intent is to explain the various points simply, rather than to elaborate them in detail. The paper is for those who want to find out about PCM rather than for those who want to design a system. Many important factors will arise in the design of a system which are not considered in this paper.read more
Citations
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Journal ArticleDOI
Least squares quantization in PCM
TL;DR: In this article, the authors derived necessary conditions for any finite number of quanta and associated quantization intervals of an optimum finite quantization scheme to achieve minimum average quantization noise power.
Least Squares Quantization in PCM
TL;DR: The corresponding result for any finite number of quanta is derived; that is, necessary conditions are found that the quanta and associated quantization intervals of an optimum finite quantization scheme must satisfy.
Journal ArticleDOI
Communication in the presence of noise
TL;DR: A method is developed for representing any communication system geometrically and a number of results in communication theory are deduced concerning expansion and compression of bandwidth and the threshold effect.
Image processing
TL;DR: Parts of image processing are discussed--specifically: the mathematical operations one is likely to encounter, and ways of implementing them by optics and on digital computers; image description; and image quality evaluation.
Journal ArticleDOI
Quantization
Robert M. Gray,David L. Neuhoff +1 more
TL;DR: The key to a successful quantization is the selection of an error criterion – such as entropy and signal-to-noise ratio – and the development of optimal quantizers for this criterion.
References
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Journal ArticleDOI
A mathematical theory of communication
TL;DR: This final installment of the paper considers the case where the signals or the messages or both are continuously variable, in contrast with the discrete nature assumed until now.
Journal ArticleDOI
Telephony by pulse code modulation
TL;DR: Experiments indicate that a three- unit code appears to be necessary for a minimum grade of circuit, while a six- or seven-unit code will provide good quality.
Journal ArticleDOI
An experimental multichannel pulse code modulation system of toll quality
L. A. Meacham,E. Peterson +1 more
TL;DR: Coding and decoding devices are described, along with other circuit details, of a 96-channel pulse Code Modulation system designed to meet the transmission requirements commonly imposed upon commercial toll circuits.
Journal ArticleDOI
PCM distortion analysis
TL;DR: In this paper, it was shown that the accepted standards of telephone transmission over wire and radio commercial systems can be obtained with a relatively small number of quantization levels, which is a recent development in the field of pulse count modulation.
Journal Article
PCM equipment
H. S. Black,J. O. Edson +1 more
TL;DR: PPCM, pulse code modulation, is a new solution to the problem of overcrowded frequency spectrum that appears to have exceptional possibilities from the standpoint of freedom from interference, and seems to have inherent advantages over other types of multiplexing.