DocumentCode
1081137
Title
Problems in realizing a digital vocoder and novel solutions
Author
Schweizer, Lutz K.
Author_Institution
Siemens A.G., Munich, Germany
Volume
19
Issue
1
fYear
1971
fDate
3/1/1971 12:00:00 AM
Firstpage
94
Lastpage
96
Abstract
Some details are given of a channel vocoder intended for use as a speech output device for data-processing systems, but also suitable for voice transmission with 2400 bit/s, e.g., in narrow-band digital radio systems or in digital encryption systems. Characteristic features are, in the analyzer, the use of switched op-amp integrators instead of conventional low-pass filters plus rectifiers, and digital amplitude compression; in the synthesizer, pulse excitation which, in the case of unvoiced sounds, is achieved by means of a pseudorandom pulse derived from a digital shift-register circuit. This pseudorandom pulse exhibits very good stability and reproducibility.
Keywords
Cryptography; Digital communication; Digital filters; Narrowband; Operational amplifiers; Pulse circuits; Pulse compression methods; Speech; Switching circuits; Vocoders;
fLanguage
English
Journal_Title
Audio and Electroacoustics, IEEE Transactions on
Publisher
ieee
ISSN
0018-9278
Type
jour
DOI
10.1109/TAU.1971.1162154
Filename
1162154
Link To Document