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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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This paper presents the simulation experiments that successfully demonstrate FM co-channel voice separation via cross coupled phase locked loops (CCPLL).
Feasibility study of direct broadcast of voice programs from unmanned satellite to home receivers
Systems feasibility analysis of voice broadcasting to home radio receivers from communication satellites
Voice broadcast satellite systems in three frequency bands, evaluating cost effectiveness in terms of audience and signal strength
Voice communication with computers, discussing advantages and difficulties
Voice broadgast mission study - summary
Voice broadcasting mission study
Technological and cost factors of voice broadcasts from satellites to earth
Two-way wireless voice communications system is automatic, provides freedom of movement, allows for complete awareness of the environment, and does not present any additional hazards such as activation of electromagnetic sensitive devices.
Eliminating baseband voice interference with telemetry for Apollo communication system
Concept, design, and specification of voice communication simulator
Phase feedback demodulation technique to analyze telemetry performance degradation caused by voice interference in modes of Apollo communication system, providing linear detection scheme
NASA balloon-aircraft ranging, data and voice experiment for determining best approach for using ATS in air traffic control
Development of voice operated controller for controlling reaction jets of spacecraft
Characteristics of electronic circuit for examining variations in vocal excitation for diagnostic purposes and in speech recognition for determiniog voice patterns and pitch changes are described. Operation of the circuit is discussed and circuit diagram is provided.
A narrow band frequency modulation communication system is described which provides for the reception of good quality voice at low carrier-to-noise ratios. The high level of performance is obtained by designing a limiter and phase lock loop combination as a demodulator, so that the bandwidth of the phase lock loop decreases as the carrier level decreases. The system was built for the position location and aircraft communication equipment experiment of the ATS 6 program.
The development of a universal voice processor is discussed. The device is based on several circuit configurations using hybrid techniques to satisfy the electrical specifications. The steps taken during the design process are described. Circuit diagrams of the final design are presented. Mathematical models are included to support the theoretical aspects.
An amplitude control technique is reported that equalizes low level phonemes in a satellite narrow band FM voice communication system over channels having low carrier to noise ratios. This method presents at the transmitter equal amplitude phonemes so that the low level phonemes, when they are transmitted over the noisey channel, are above the noise and contribute to output intelligibility. The amplitude control technique provides also for squelching of noise when speech is not being transmitted.