Accession Number:

AD0416647

Title:

STUDIES IN DIGITAL COMMUNICATIONS. PART I. FEASIBILITY OF ASYNCHRONOUS MULTIPLEXING. PART II. PERFORMANCE OF HIGH-SPEED DIGITAL COMMUNICA TIONS OVER TROPOSCATTER LINKS,

Descriptive Note:

Corporate Author:

MICHIGAN UNIV ANN ARBOR COOLEY ELECTRONICS LAB

Personal Author(s):

Report Date:

1963-08-01

Pagination or Media Count:

1.0

Abstract:

Part I describes experiments and calculations aimed at demonstrating the feasibility of asyn chronous time multiplexing for multichannel speech. The work here generally served to elaborate on the theoretical analysis and pre dictions made previously, and demonstrated them in the laboratory. The experiments tested vari ous aspects of the method, and culminated in a realistic multichannel experiment with extermal coded speech signals. The major feasibility demonstrations were done by using a digital com puter with A-D equipment. However, an analog extremal coding system was built in order to demonstrate the equipment simplicity. The work here showed that asynchronous time multiplexing is feasible, under the conditions treated, for systems having as few as 24 sources. It ss concluded that the advantage of this method over synchronously multipl xed PCM is about 2.7 for 100 sources, and 2.1 and 24 sources. Increases in this advantage should be possible with system improvements. The speech quality with this advantage is not distinguishable, with casual listening, from that of the usual PCM. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE