Accession Number : ADD010995

Title :   Synchronous/Asynchronous Independent Single Sideband Acoustic Telemetry.

Descriptive Note : Patent,


Personal Author(s) : Mackelburg,G R ; Watson,S J ; Gordon,A

Report Date : 14 Feb 1984

Pagination or Media Count : 11

Abstract : An undersea communications system provides for improved data transmission capabilities. Two separate sources of information respectively modulate the upper and the lower sidebands of an acoustic carrier. The discretely modulated sidebands are simultaneously transmitted without the acoustic carrier or the acoustic carrier can be added to allow asynchronous or synchronous demodulation and use of the two modulating informations. Separation of the information in the two discretely modulated sidebands is assured by shifting the modulating information to ultrasonic regions and filtering out upper and lower sidebands of modulating information. Next, the shifted sidebands are modulated by an acoustic carrier which, optimally, is transmitted along with the discretely modulated upper and lower side-bands. A phase locked loop in the receiver portion assures synchronous demodulation or a crystal oscillator allows asynchronous demodulation of the discretely modulated upper and lower sidebands. (Author)

Descriptors :   *Patents, *Acoustic communications, *Underwater communications, *Single sideband communications, *Telemeter systems, Data transmission systems, Asynchronous systems, Bandpass filters, Carrier frequencies, Crystal oscillators, Phase locked systems, Electroacoustic transducers, Synchronism, Demodulation, Ultrasonics, Loops, Separation, Sources, Electroacoustics, Acoustics, Modulation, Sidebands, Regions

Subject Categories : Acoustics
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE