| 摘要 |
There are provided a high frequency signal interpolation method and a high frequency signal interpolation device for forming a preferable high frequency signal with a simple configuration and favorably performing practical high frequency signal interpolation. Therefore, according to the present invention, a compressed digital audio signal reproduced from a digital audio device is supplied as a raw signal to an input terminal 1. The raw signal is supplied, for example, to a Hilbert conversion circuit 2 for generating an analytic signal. A real part R and an imaginary part I of the analytic signal are taken out, independently. Furthermore, the real part R and the imaginary part I are supplied to square circuits 3 and 4, respectively. Subsequently, squared signals are added in an adder circuit 5, respectively. The added signal is supplied to a square-root circuit 6 and an envelope component of the raw signal is taken out. A harmonic component is formed in the envelop component. Thus, a high-harmonic portion of the envelope component taken out at the square-root circuit 6 is taken out by a high-pass filter (HPF) 7. On the other hand, a signal from which a high frequency portion of the raw signal from the input terminal 1 is removed by a low-pass filter 8 is formed. These signals are added by an adder circuit 9 and then output to an output terminal 10. Accordingly, the interpolation is carried out by forming the envelope component of the raw signal using the real part and the imaginary part of the analytic signal of the raw signal; and taking the high-harmonic portion out of the formed envelope component. Therefore, a favorable high frequency signal is formed by an extremely simplified configuration and practical high frequency signal interpolation can be carried out. |
