The Philosophy of PCM

  title={The Philosophy of PCM},
  author={B. M. Oliver and John R. Pierce and Claude E. Shannon},
  journal={Proceedings of the IRE},
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… 
Weighted PCM
A modified form of pulse-code modulation, called weighted pcm, is described in which the relative amplitudes of the pulses within the pulse-code groups are adjusted so as to minimize the noise power
Pulse Code Modulation
The term pulse code modulation (PCM) refers to the use of a specific set of rules for transforming a waveform into a stream of digits, and vice versa. To clarify the concept, however, the first point
Analysis of a PCM System Employing a PPM Vernier
The Vernier system's performance exceeds that of pure PCM and of pure PPM consistently and considerably, and can be realized as an increase in output SNR, as a decrease in time-bandwidth occupancy, or as a combination of these advantages.
A PCM Experiment for the Senior Electronic Laboratory
An experiment on pulse-code modulation designed for the senior-year electronics student is described. PCM is pedagogically desirable for its embodiment of a wide variety of pulse and digital
Performance of Multilevel PCM
  • G. Sage
  • Computer Science, Engineering
    IEEE Transactions on Aerospace and Electronic Systems
  • 1966
The performance of multilevel PCM is compared with other systems on an equal bandwidth basis and it is found that multileVEL PCM requires less input power than any commonly used modulation system of equal bandwidth.
Advances in Digital Communication (Part 1)
The paper discusses the present day state-of-the-art and the progress made in the inter-related areas of digital communication, such as source encoding, signal design, data communication,
Predictive quantizing systems (differential pulse code modulation) for the transmission of television signals
A procedure is presented for the design of nonadaptive, time invariant systems which are near optimum in the sense that the resulting signal to unweighted quantizing noise ratios (S/N) are nearly maximum.
A comparative simulation study of the real effect of PCM, DM and DPCM systems on audio and image modulation
The implementation of the aforementioned systems using Simulink (The Math Works, Inc., USA) on a multithreaded processor computer is discussed, to prove the importance of DPCM over PCM system in eliminating such effects and ensuring a successful transfer of data.
The past, present and future of PCM
The pulse code modulation future depends a great deal on how well or how badly its main planning problems are tackled during the next decade or so, and there is little or no agreed view on the technical and more general points involved in this planning.


PCM distortion analysis
PCM, pulse count modulation, is a recent development in the field of pulse time multiplexing. Computations and experimental work indicate that accepted standards of telephone transmission over wire
Telephony by pulse code modulation
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.
PCM equipment
PCM, pulse code modulation, is a new solution to the problem of overcrowded frequency spectrum. It appears to have exceptional possibilities from the standpoint of freedom from interference, and
An experimental multichannel pulse code modulation system of toll quality
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.
A mathematical theory of communication
In this final installment of the paper we consider the case where the signals or the messages or both are continuously variable, in contrast with the discrete nature assumed until now. To a