METHOD AND APPARATUS FOR CORRECTING SIGNALS, APPARATUS FOR COMPENSATING FOR DISTORTION, APPARATUS FOR PREPARING DISTORTION COMPENSATING DATA, AND TRANSMITTER

An apparatus for correcting signals includes a unit for estimating distortion characteristics in high-frequency circuit portion which estimates distortion characteristics of a high-frequency circuit portion concerning amplitude distortion or phase distortion impairing linearity. The apparatus further includes an input signal processor for applying an amplitude distortion correcting function or phase distortion concerning function, which is calculated on the basis of the result of estimating the distortion characteristics, to an input signal such as low-pass signals.