| 摘要 |
<p>A digital broadcast receiver is characterized in having a signal level detection circuit which performs gain control to make the power levels of received signals constant, judges whether an automatic gain control value obtained by the gain control is larger than a threshold stored in advance and outputs a judgment result, a peak detection part which detects the peaks of the power levels within a band of the received signals and outputs the detected peaks, an abnormal peak judgment part which judges whether the peaks outputted from the peak detection part include a peak larger than a threshold stored in advance and outputs the judgment result, a specific peak judgment part which judges whether the peaks outputted from the peak detection part include a peak exceeding a threshold stored in advance in a specific frequency band and outputs the judgment result, and a part for judging power within a prescribed band, which judges whether the total level of the whole power within the predetermined band is larger than a threshold stored in advance and outputs the judgment result. The digital broadcast receiver is also characterized in judging whether a signal being received is a digital broadcast signal on the basis of the judgment results outputted respectively from the signal level detection circuit, the abnormal peak judgment part, a specific peak judgment part and the part, for judging power within the prescribed band.</p> |
