| 摘要 |
<p>PURPOSE: To enable a numeric data demodulator to instantaneously detect a disturbance signal. CONSTITUTION: A demodulator is composed of a circuit 10 for shaping, crossing, and sampling input signals, a circuit 20 for synchronizing and shaping reference signals, a disturbance signal detecting circuit 30, and a demodulation circuit 40. In a method for detecting disturbance signal, an already known signal is periodically inserted and a disturbance signal is detected from modulated signals fixed before demodulation. In addition, the method includes the following steps: a step in which the square of the cross correlation module between an expected signal and a received reference signal is evaluated in a specific moment when the existence of the reference signal is recognized, a step in which the square of a simultaneously received signal is evaluated and the evaluated value is multiplied by a factor indicating the square of the evaluated value of the factor, and then, the product is multiplied by the number R of a reference symbol used for a reference burst, and a step in which the quantities simultaneously obtained in the above two steps are compared with each other.</p> |
