| 摘要 |
PROBLEM TO BE SOLVED: To provide an orthogonal frequency-division multiplex modulator circuit for reducing a power consumption, by preventing an increase in a circuit scale of a logic circuit section by using one or more interpolators 5, 9, having IIR digital full band-pass filters 51 , 53 , 91 , and 93 having a little number of tap stages as the interpolators. SOLUTION: The orthogonal frequency-division multiplex modulator circuit comprises an inverse Fourier transforming means 3 for inverse Fourier transforming a digital modulation signal, by mapping the signal to a plurality of subcarriers and outputting inverse Fourier transformation signals of a plurality (N) of points, and an interpolating means for interpolating the N points of the inverse Fourier transformation signals in an interpolating order 2. The interpolating means has only an initial stage interpolator 5 or a combination stage of one or more complex multipliers 6 cascade connected to the initial stage interpolator 5 and the next stage interpolator 9 connected to the multipliers 6. The interpolators 5, 9 have 90 deg.-phase-shift IIR digital full band-pass filters 51 , 53 , 91 , and 93 , and digital delay circuits 52 , 54 , 92 , and 94 , for delaying by the signal delays of the IIR digital full band-pass filters 51 , 53 , 91 , and 93 .
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