| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably detect a synchronizing signal and to correctly demodulate transmitted information in synchronous with the detected synchronizing signal even if a reception electric field strength is in a fluctuating condition. SOLUTION: A tuner 102 selects a frequency out of digital broadcasting waves. An A/D converter 110 converts it into a digital signal. A null signal generation part 105 detects a null signal in a signal outputted from the tuner 102. A travelling speed detection part 122 detects a travelling speed of a broadcasting receiver. A fading decision part 120 decides a fading level corresponding to the travelling speed and selects the number of frames. A null signal average generation part 106 averages the null signals for the number of frames, regards a signal having a maximum amplitude as a synghronizing signal and a demodulation part 111 orthogonal frequency division multiplexing(OFDM) demodulates a digital signal on the basis of a timing of the synchronizing signal.</p> |
