| 摘要 |
PROBLEM TO BE SOLVED: To eliminate discontinuity of compensation data in algorithm for updating the compensation data about an approximation calculation section set by unit of a plurality of fixed addresses. SOLUTION: A compensation data table 8 stores the compensation data for canceling nonlinear distortion components which are generated by a power amplifier 4 by every address corresponding to an inputted signal level. A pre-distorter 1 provides distortion to an inputted signal S1 by the compensation data to be supplied from the compensation data table 8. A comparator circuit 101 of a compensation data update part 10 detects difference (distortion components) by comparing the inputted signal S1 with an output signal S3 of an A/D converter 7. An approximation calculation section setting circuit 102 shifts the approximation calculation section in the case of performance of update processing. A function approximation circuit 103 updates the compensation data by performing a function approximation calculation about the compensation data in the set approximation calculation section. COPYRIGHT: (C)2005,JPO&NCIPI
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