| 摘要 |
PURPOSE:To speed up synchronization between a received signal and a reference code by providing a code generating means to generate the reference code, a convolving means to take correlation between the received signal and the reference code, a peak detecting means and a code synchronizing means. CONSTITUTION:The convolver 11 takes the correlation between a received diffused signal and the reference code generated by a generator 17, and the peak detection circuit 13 detects the peak of the output of the convolver 11, and outputs it. Next, a phase comparator 14 controls a voltage controlled oscillator 16 so that a clock which is generated by a frequency divider 18 and synchronizes with the reference code coincides with the clock which is generated by the circuit 13 and synchronizes with the received diffused signal. Besides, a diffused code generator 17 outputs a reference diffused code system starting point signal to a variable delay circuit 111 so as to synchronize with time when one period of the reference diffused code coincides with the integration area of the convolver 11. The circuit 111 operates so as to delay an input signal by twice longer time then the time from the input of the signal till the rise-up of the output of the frequency divider 18. Thus, synchronism acquisition is attained, and the synchronization between the received signal and the reference code can be made fast. |
