| 摘要 |
PROBLEM TO BE SOLVED: To compensate complicated non-linear distortion having a memory effect by a simple constitution. SOLUTION: In compensating distortion generated in an amplifier for composing outputs from a plurality of amplification elements, predistortion is added to an input signal by using a signal composed by multiplying a signal for compensating distortion generated in respective amplification elements by a composite coefficient which is a function of an instantaneous amplitude. Concretely, the predistorter comprises: a power detection part (301) for detecting the instantaneous amplitude or the like of the input signal and time-sequentially outputting the detected value as x; a plurality of history-added non-linear distortion generation parts (328 to 333) for generating non-linear distortion having a history characteristic or a frequency characteristic according to present and past x; non-linear weighting composition parts (327, 334 to 336) for generating non-linear weight according to the present x and composing the distortions generated by the history-added non-linear distortion generation parts (328 to 333) by using the weight; and distortion-providing parts (325 to 326) for providing predistortion based on outputs of the non-linear weighting composition parts (327, 334 to 336). COPYRIGHT: (C)2007,JPO&INPIT
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