| 摘要 |
PURPOSE:To correctly set the phase of an output carrier wave from a local oscillator to an orthogonal demodulator for compensating non-linear distortion even in the case of continuous transmission in which there is no lamp bit in the case of burst transmission. CONSTITUTION:This method is provided with a monitor 1 for monitoring the levels of signals I and Q in two analog systems inputted to an orthogonal modulator 50, and the monitor detects the state of turning the levels of both of analog signals of two systems inputted to the orthogonal modulator 50 to a level higher than a prescribed threshold value Vth. In such a state, phase difference is measured between the phases of outputs I' and Q' of an orthogonal demodulator 70 and the phase of the input of the orthogonal modulator, and the phase of the output of the orthogonal demodulator is set so as to eliminate the phase difference. |
