| 摘要 |
PURPOSE: To enable stable distortion compensation control by sampling input level detection at timing divided more than the number of slots per frame at least and deciding its maximum value as the input signal level of that frame. CONSTITUTION: On the input side, a level detector 13 for detecting the input level of a multifrequency input signal is added, a temperature sensor 14 for detecting the temperature near a main amplifier 3 is provided, and a control circuit 12 is equipped with a non-volatile memory 15 such as a battery backup RAM or EEPROM. This non-volatile memory 15 previously stores optimum vector adjusting data with the input level and the temperature level as parameters to be applied to vector adjusters 2 and 7 while estimating the change of the input level and the temperature change, and the adjustment data are read out corresponding to the detected level. Namely, when an input level Pin is high, a distortion detection loop and a distortion removal loop are optimumly adjusted for the unit of a frame so that no distortion can be generated even when the input at a level lower than that input level enters. |
