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US 3,946,162 AGranted
System for transferring wideband sound signals
AssigneeInternational Standard Electric Corporation
InventorGerhard-Gunter Gassman
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AssigneeInternational Standard Electric Corporation
InventorGerhard-Gunter Gassman
Estimating the term…
A system for transmitting wideband signals, for example speech, over a narrow band is proposed. Lower frequency range signals are directly transmitted and amplitude information of partial upper frequency ranges is transmitted on pilot frequencies. At a receiver, "equivalent" signals from oscillators having frequencies approximately equal to the mid range frequencies of the partial upper frequency ranges are modulated with the amplitude information of the corresponding partial upper frequency ranges to produce "synthetic" signals. The synthetic signals are modulated with narrow band noise to crreate a more pleasing and realistic sound. Means are provided for controlling at the pick-up end the "modulation factor" of the noise modulation at the reproducing end. This is achieved by controlling the level of the third harmonic of a sync signal transmitted from the pick-up end. The level of the third harmonic may be automatically or manually adjusted to conform to the type of sound being transmitted.
A receiver for use in a system having a transmitter of the type that transfers lower frequency range sound signals directly and at least one pilot frequency signal modulated by an amplitude signal corresponding to the amplitude of the sound signals in a higher frequency range, said receiver comprising:
A transmitter for transferring wideband sound signals over a narrow frequency range, comprising:
A system for transferring and receiving wideband sound signals over a narrow frequency range, comprising:
A receiver for use in a system having a transmitter of the type that transfers lower frequency range sound signals directly and the higher frequency range signals are divided into a plurality of partial higher frequency ranges and amplitude signals corresponding to the amplitudes of the sound signals in the partial higher frequency ranges are transmitted on at least one modulated pilot frequency, said receiver comprising:
A receiver for use in a system having a transmitter of the type that transfers lower frequency range sound signals directly and at least one pilot frequency signal modulated by an amplitude signal corresponding to the amplitude of the sound signals in a higher frequency range and that provides a signal corresponding to a desired noise modulating factor, said receiver comprising:
In a receiver of the type that receives a pilot signal sequentially modulated with amplitude signals corresponding to the amplitudes of sound signals in a predetermined number of partial frequency ranges and reproduces the sound signals in said partial frequency ranges by simulating said partial frequency ranges with equivalent frequency signals having frequencies approximately equal to the mid range frequencies of the partial frequency ranges, said equivalent signals being amplitude modulated to correspond to the amplitude of the signals in the partial frequency ranges, the improvement comprising:
A receiver for use in a system having a transmitter of the type that transfers lower frequency range sound signals directly, a pilot frequency signal sequentially modulated by amplitude signals corresponding to the amplitudes of sound signals in a predetermined number of partial higher frequency ranges, a sync signal corresponding to the repetition rate of the sequential modulation of the pilot frequency signal and a signal containing noise modulation factor information, said receiver comprising:
Dependencies are inferred from the claim text.