| 摘要 |
Amplitude level of a received signal is controlled by a variable gain amplifier (12), the received signal with the amplitude level controlled is converted to a digital signal by an A/D converter (13), and correlation or demodulation is established by a correlator (14) on the digital value. A correlated output comparator (15) compares an output signal from the correlator with a prescribed threshold value to establish correlated synchronization using the output signal from the correlator, performs initial synchronization using the comparison output, the output amplitude level of the variable gain amplifier (12) is controlled in accordance with an output amplitude from the correlator (14), and gain of the variable gain amplifier (12) is switched to the maximum value by a switch (19) dependent on presence/absence of a synchronization establishment signal from the correlation synchronizing circuit (16). <IMAGE> |
