| 摘要 |
<p>A radio transmission apparatus employing pre-distortion does not update the distortion compensation coefficient for a certain period, which is shorter than the transmission period, after the transmission period start timing. Instead, update operation of the distortion compensation coefficient is carried out after the lapse of a certain period from the start timing, thus avoiding, for example, switching-induced fluctuations at the start of the transmission period in a TDD system. Further, in order to shorten the convergence time of the distortion compensation coefficient, the radio transmission apparatus performs interpolation processing of the distortion compensation coefficient. The distortion compensation coefficient is given to a two-dimensional coordinate (address) : one co-ordinate is the power level of an input transmission signal and the other is the difference of power between the input transmission signal and a feedback signal. The distortion compensation coefficient at a predetermined coordinate is updated to an interpolated value, which is obtained through interpolation calculation using the distortion compensation coefficient at a coordinate adjacent to the predetermined coordinate.
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