Accession Number:

AD0766256

Title:

Description of a Speech Modulation Experiment Involving Infinite Clipping,

Descriptive Note:

Corporate Author:

AEROSPACE CORP EL SEGUNDO CALIF SYSTEMS ENGINEERING OPERATIONS

Report Date:

1973-09-01

Pagination or Media Count:

42.0

Abstract:

A speech modulation system designed to operate a low carrier-to-noise ratios is described. Infinite speech clipping and phase-shift keying are used in the system, which occupies a bandwidth of 10 kHz. Sample speech tapes were produced at simulated carrier-to-noise ratios varying from 10 to -3 dB. The corresponding ratio of carrier power to noise power per unit bandwidth was varied from 50 to 37 dB above 1 Hz. In the simulated circuit, a 20-kHz biasing tone is used to suppress noise during pauses in speech. A phase lock loop in the receiver that is used to derive the detector reference is described. Some preliminary results determined by the use of the simulated link are presented. Author

Subject Categories:

  • Voice Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE