| 摘要 |
A distortion compensating circuit wherein even in a situation where the frequency of occurrence of an input signal having the maximum value is low, a model update is complimented, thereby achieving a high-precision distortion compensation. A DPD processing unit (2) comprises: an inverse model estimating unit (22) that estimates, based on an input signal (S1) to and an output signal (S10) from an HPA (6), a reverse model to a model representing an input/output characteristic of the HPA (6); a distortion compensating unit (26) that adds the reverse model to the input signal (S1), thereby compensating for the distortion of the input/output characteristic; and a sampling circuit (20) that samples the latest signals (S2, S10) occurring within a predetermined time period and inputs the sampled signals (S2, S10) to the inverse model estimating unit (22). The inverse model estimating unit (22) updates, based on the signals (S2, S10) from the sampling circuit (20), the reverse model independently of whether the possible maximum value of the input signal (S1) is included in a range of the signals as sampled by the sampling circuit (20).
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