7results about "Volume compression/expansion without controlling loop" patented technology

A transmitter is provided that determines a compression of an envelope-tracking amplifier using a function of the amplifier's power supply voltage, input signal voltage, and output signal voltage. An input signal adjustment circuit adjusts the input signal to the envelope-tracking amplifier responsive to a difference between the compression and a desired fixed value for the compression.

An example detector cell includes a first current source circuit having a terminal. The detector cell includes a first transistor having a control terminal, a first terminal, and a second terminal coupled to the terminal of the first current source circuit. The detector cell includes a second current source circuit having a terminal coupled to the first terminal of the first transistor. The detector cell includes a first current mirror having a first terminal and a second terminal, the first terminal coupled to the terminal of the second current source circuit and the first terminal of the first transistor. The detector cell includes a second transistor having a control terminal, a first terminal, and a second terminal coupled to the terminal of the first current source circuit. The detector cell includes a third current source circuit having a terminal coupled to the first terminal of the second transistor. The detector cell includes a second current mirror having a first terminal coupled to the terminal of the third current source circuit and the first terminal of the second transistor and a second terminal coupled to the second terminal of the first current mirror.

The present application discloses an audio signal processing method and an audio signal processing device for carrying out the audio signal processing method. The audio signal processing method comprises: receiving an audio signal and compressing the audio signal to produce a first compressed signal; calculating a duration for which a power value of the first compressed signal equals a first power threshold; determining whether the duration exceeds a first time threshold; if the duration exceeds the first time threshold, compressing the first compressed signal to produce a second compressed signal; and amplifying and outputting the second compressed signal. The method described above reduces the volume and prevents damage to electronic components during prolonged high-power operation of the loudspeaker system.

There is provided a method, apparatus and computer program for causing an apparatus to perform: obtaining at least one audio signal; compressing the at least one audio signal using at least one first algorithm to output at least one compressed audio signal, wherein a summation of two or more compressed audio signals is largely homomorphic to a summation of two or more audio signals; and encrypting the at least one compressed audio signal using a homomorphic encryption algorithm to form at least one encrypted audio signal.

A logarithmic amplifier (200) includes a logarithmic current preamplifier circuit (202) and a logarithmic amplifier circuit (204). The logarithmic current preamplifier circuit (202) includes an inverting input terminal (206A), an output terminal (206B), and a first diode (210). The first diode (210) is coupled between the inverting input terminal (206A) and the output terminal (206B) of the logarithmic current preamplifier circuit (202). The logarithmic amplifier circuit (204) includes an inverting input terminal (212A), an output terminal (212B), and a second diode (214). The inverting input terminal (212A) of the logarithmic amplifier circuit (204) is coupled to the output terminal (212B) of the logarithmic current preamplifier circuit (202). The second diode (214) is coupled between the inverting input terminal (212A) and the output terminal (212B) of the logarithmic amplifier circuit (204).

There is provided a method, apparatus and computer program for causing an apparatus to perform: obtaining at least one audio signal; compressing the at least one audio signal using at least one first algorithm to output at least one compressed audio signal, wherein a summation of two or more compressed audio signals is largely homomorphic to a summation of two or more audio signals; and encrypting the at least one compressed audio signal using a homomorphic encryption algorithm to form at least one encrypted audio signal.

A transmitter is provided that determines a compression of an envelope-tracking amplifier using a function of the amplifier's power supply voltage, input signal voltage, and output signal voltage. An input signal adjustment circuit adjusts the input signal to the envelope-tracking amplifier responsive to a difference between the compression and a desired fixed value for the compression.