| 摘要 |
PURPOSE:To detect a synchronizing circuit through small-scale circuit constitution by employing a pattern which is never generated during code conversion as a synchronizing pattern and counting the frequency of the occurrence of an error of demodulation characteristic to the synchronizing signal pattern during the demodulation. CONSTITUTION:A reproduced code to be converted from an input terminal 12 is inputted to a 12-stage shift register 13 (for demodulation) and outputted through a code converting circuit 14 as demodulation data, which is supplied to an output terminal 16 through a 4-stage shift register circuit 15 (for demodulation). As the synchronizing signal, the 32-bit synchronizing signal which is never generated in the converted code is used. A patternIbecomes an error during demodulation and a demodulation error signal is outputtd from the circuit 14 to a counting circuit 17. The circuit 17 generates an output signal after counting ever eight signals successively. A pattern coincidence circuit 8 (for synchronizing detection) sends out a synchronizing signal detection output to an output terminal 19 when detecting the signal of the circuit 17, the 4-bit output of the circuit 13, and a pattern II. Thus, the synchronizing signal is detected through the simple circuit constitution. |
