| 摘要 |
PROBLEM TO BE SOLVED: To reduce distortion of an output signal due to memory effect of a power amplifying device. SOLUTION: The output signal of a PA 106 is transmitted only in a desired signal band selectively to a radio communication line through a first BPF 300 and an ANT 108. A portion of the output signal, on the other hand, is input to a BPF 302 through a directional coupler 110 and a downconverter 120, and only the desired signal band is selectively passed and converted by an A/D 122 into data in digital form to obtain feedback data. A control unit 124 uses the feedback data to update an LUT 128. The LUT 128 outputs compensation data corresponding to amplitude value data E indicative of an amplitude value of input data that an envelope detector 126 detects, to a predistorter 100. The predistorter 100 compensates the input data using the compensation data so that distortion of the output signal of the PA 106 becomes small. COPYRIGHT: (C)2009,JPO&INPIT
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