Audio signal processing circuit
View Patent ↗An audio signal processing circuit is provided which comprises an ADC which samples an audio signal at a predetermined sampling frequency, a high-band compensation processor which compensates a signal sampled by the ADC to a frequency band which is higher than a signal band sampled by the sampling frequency, and an encoding unit which encodes a signal processed by the high-band compensation processor.
1. An audio signal processing circuit comprising:
an analog-to digital converter which converts an audio signal into a digital audio signal of a predetermined sampling frequency;
a high-band compensation processor which compensates the digital audio signal converted by the analog-to-digital converter to a frequency band which is higher than a signal band sampled by the sampling frequency; and
an encoding unit which encodes the audio signal processed by the high-band compensation processor, wherein
the audio signal processing circuit is configured to inhibit power consumption by processing the audio signal at the analog-to-digital converter in a frequency band lower than at the encoding unit; and
the audio signal processing circuit is configured to obtain a high-quality audio signal by processing the audio signal at the encoder in a frequency band higher than at the analog-to-digital converter.
2. The audio signal processing circuit according to claim 1 , wherein
the high-band compensation processor comprises:
a down-sampling unit which generates a signal in which a part of the audio signal converted by the analog-to-digital converter is removed;
an up-sampling unit which inserts a 0-signal to a signal portion removed by the down-sampling unit; and
a filtering unit which applies a filtering process to the signal processed by the up-sampling unit.
3. The audio signal processing circuit according to claim 2 , wherein
the high-band compensation processor can select whether or not the high-band compensation processor applies the compensation process, and
the analog-to-digital converter changes the sampling frequency based on whether or not the high-band compensation processor applies the compensation process.
4. The audio signal processing circuit according to claim 1 , wherein
the high-band compensation processor can select whether or not the high-band compensation processor applies the compensation process, and
the analog-to-digital converter changes the sampling frequency based on whether or not the high-band compensation processor applies the compensation process.