| 摘要 |
PURPOSE: To provide an adaptive distortion compensation unit that converts the output of a power amplifier into a signal in a base band without the use of an orthogonal demodulator. CONSTITUTION: The adaptive distortion compensation unit is provided with a 1st envelope detection means DET 1 that receives a high frequency input signal whose envelope is fluctuated to obtain a 1st envelope detection signal, a read/write storage means RAM 1 that receives an address signal on the basis of the 1st envelope detection signal to read an output data signal and to write a write data signal, a latch means LCH that latches an output data signal read from the storage means RAM 1, a 2nd envelope detection means DET 2 that receives an output signal of a power amplifier PA whose distortion is to be compensated to obtain a 2nd envelope detection signal, and a differential code detection logic conversion means that provides outputs of digital levels +1, -1 depending on the polarity of a difference between the 1st and 2nd envelope detection signals. The output signals from the latch means and the code detection logic conversion means are summed up and written in the storage means RAM 1.
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