Device for recovering missing frequency components
AssigneeOki Electric Industry Co., Ltd.
InventorMasashi Takada
Life of this patent
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Abstract
A band recovering device recovers frequency components lying in a frequency band lost due to band-limitation of a sound signal. The device includes a peak-limiting amplifier for amplifying an input narrow-band signal while preventing the resulting amplified signal from exceeding a maximum amplitude. A peak-limitation detector detects the level of the amplified signal output. An amplification controller increases the amplification factor and/or the amount of amplification of the peak-limiting amplifier in accordance with the level of the amplified signal. A band recovering circuit generates, based on the amplified signal output from the peak-limiting amplifier and input narrow-band signal, a band-recovered signal including the frequency components lying in the missing band.
Claims16
A band recovering device for recovering frequency components lying in a frequency band lost due to band-limitation of a sound signal, comprising:
- a peak-limiting amplifier configured to amplify an input narrow-band signal while preventing a resulting amplified signal from exceeding a maximum amplitude;
- a peak-limitation detector configured to detect a level of the amplified signal output from said peak-limiting amplifier;
- an amplification controller configured to increase at least either one of an amplification factor and an amount of amplification of said peak-limiting amplifier in accordance with the level of the amplified signal output from said peak-limitation detector;
- and
- a band recovering circuit configured to generate, based on the amplified signal output from said peak-limiting amplifier and the input narrow-band signal, a band-recovered signal including the frequency components lying in the frequency band lost.
A telephone set comprising a band recovering device for recovering frequency components lying in a frequency band lost due to band-limitation of a sound signal, wherein said band recovering device comprises:
- a peak-limiting amplifier configured to amplify an input narrow-band signal while preventing a resulting amplified signal from exceeding a maximum amplitude;
- a peak-limitation detector configured to detect a level of the amplified signal output from said peak-limiting amplifier;
- an amplification controller configured to increase at least either one of an amplification factor and an amount of amplification of said peak-limiting amplifier in accordance with the level of the amplified signal output from said peak-limitation detector;
- and
- a band recovering circuit configured to generate, based on the amplified signal output from said peak-limiting amplifier and the input narrow-band signal, a band-recovered signal including the frequency components lying in the frequency band lost.
A band recovering device for recovering frequency components lying in a frequency band lost due to band-limitation of a sound signal, comprising:
- an amplitude limiter configured to limit an upper limit of a signal value of the input narrow-band signal;
- a detector configured to detect a level of the signal value of the input narrow-band signal;
- an amplitude-limit controller configured to decrease the upper limit in accordance with an output of said detector;
- and
- a band recovering circuit configured to generate, based on a signal output from said amplitude limiter and the input narrow-band signal, a band-recovered signal including the frequency components lying in the frequency band lost.
A telephone set comprising a band recovering device for recovering frequency components lying in a frequency band lost due to band-limitation of a sound signal, wherein a band recovering device comprises:
- an amplitude limiter configured to limit an upper limit of a signal value of the input narrow-band signal;
- a detector configured to detect a level of the signal value of the input narrow-band signal;
- an amplitude-limit controller configured to decrease the upper limit in accordance with an output of said detector;
- and
- a band recovering circuit configured to generate, based on a signal output from said amplitude limiter and the input narrow-band signal, a band-recovered signal including the frequency components lying in the frequency band lost.
Dependencies are inferred from the claim text.