| 摘要 |
PURPOSE:To make it possible to quickly obtain synchronism by using a modulated wave in a sequence having a sharp self-correlation as a synchronizing signal. CONSTITUTION:When an input waveform X(t) is inputted to a detector at the time of selecting a barker code with length '5' as a code string, the output waveforms of respective delay circuits 13a to 13d respectively become X(t-tau) to X(t-4tau). The output waveforms of the delay circuits 13a to 13d are added by an adder 14 though the output waveform of the circuit 13a is added after being inverted at its code, and when a waveform corresponding to the final symbol of a barker code is inputted to the detector, the a sine waveform having 5 times the amplitude of an input wave is outputted from the adder 14 as an output waveform y(t) only for time tau. Thereby, the sine wave is detected and its detecting timing is used for reproducing a carrier and symbol timing. Since synchronism is executed by using a sequence having a sharp correlating function such as a barker code, time required for the synchronism can be shortened. |
