| 摘要 |
PURPOSE:To prevent deterioration of the transmission spectrum by distorting in advance not only the symbol point but also the waveform of a signal between the symbol points. CONSTITUTION:A shift register 120 stores the data for a share of K-pieces of signals (K is a constant <=1). A ROM 130 receives the output from a counter 110 and outputs the transmission signal waveform sampled for a duration of one symbol correspondent to a shift pattern, and in a RAM 140, it is made a complex signal waveform and outputted. The output from the RAM 140 is converted to an analog data by a D/A converter 150, modulated by a modulator 160, and outputted from a terminal 102 to a non-linear amplifier that is not shown in the figure. Also, the output from the non-linear amplifier inputted from a terminal 103 is in part demodulated by a demodulator 165, and digitized by an A/D converter 155. A subtracting circuit 170 compares said output from the converter 155 and that from the ROM 130. The output from the circuit 170 is multiplied by a constant P (constant<=1) by a correction-amount generating circuit 180, is added to the output from the RAM 140 by an adder 190. And the output from the adder 190 is written in the RAM 140. |
