Patent ID: 8036324

Claim:
A digital broadcasting receiving apparatus which receives digital broadcasting, comprising: a signal level detecting circuit configured to perform gain control to maintain a power level of a received signal at a fixed level, to decide whether an automatic gain control level of the gain control is greater than a prestored signal level threshold, and to output a result of the signal level detecting circuit decision; a peak detecting section configured to detect a peak of a power level within a frequency band of the received signal, and to output the detected peak; an abnormal peak deciding section configured to decide whether there is a peak greater than a prestored abnormal peak decision threshold in the peak output from the peak detecting section, and to output a result of the abnormal peak deciding section decision; a specified peak deciding section configured to decide, within a specified frequency band whether there is a peak exceeding a prestored peak detection threshold in the peak output from the peak detecting section, and to output a result of the specified peak deciding section decision; a prescribed in-band power deciding section configured to decide whether a sum total of all powers within a prescribed band is greater than a prestored prescribed in-band power threshold, and to output a result of the prescribed in-band power deciding section decision; and a broadcast wave deciding section configured to decide that there is a digital broadcasting signal on condition that: the signal level detecting circuit decides that there is a signal, the abnormal peak deciding section decides that there is not an abnormal peak, the prescribed in-band power deciding section decides that there is a prescribed in-band power, and the broadcast wave deciding section obtains an OFDM frame lock signal and a broadcasting station information within a fixed time period; or the signal level detecting circuit decides that there is a signal, the abnormal peak deciding section decides that there is not an abnormal peak, the prescribed in-band power deciding section decides that there is not a prescribed in-band power, the specified peak deciding section decides that there is not a specified peak, and the broadcast wave deciding section obtains an OFDM frame lock signal and a broadcasting station information within a fixed time period.