| 摘要 |
PURPOSE: A gain control signal generating device of multi level demodulator is provided to minimize influence due to signal even in case of having multi level signal points such as Quadrature Amplitude Modulation(QAM) and control gain only with influence due to noise. CONSTITUTION: A gain control signal generating device of multi level demodulator comprises a signal power calculator(1), an error detector(2), a loop filter(3), a pulse width modulator(4) and a signal/noise divider(10). The calculator(1) outputs signal power from in phase and quadrature phase. The filter(3) is a low pass filter for filtering error components. The modulator(4) modulates the pulse width of the signal filtered in the loop filter to output gain control signals. The divider(10) receives the signal power and divides the power into signal and noise components to output them to the error detector.
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