| 摘要 |
PURPOSE:To secure the stable tracing of synchronization by capturing the synchronization of a pseudo noise (PN) code then tracing it with a delay lock loop for a prescribed time, then switching to a costas loop to maintain the locked status of synchronization. CONSTITUTION:A PN generator 15 supplies a PN code to a correlator 1 in order to obtain the sliding correlation between a PN code on the transmission side and that on the reception side, the detection of synchronization is executed by using the output of a detector 7, and thus capture the synchronization of the PN code, thereafter, a control circuit 25 controls so that the titled tracer enters into a tracing state by means of the delay lock loop 100. After the lapse of the response time of a loop filter 11, a sample holder 12 is actuated to supply a sample holding voltage to an adder 13. Simultaneously or almost simultaneously with it, an electronic switch 26 is turned from ON-state to OFF-state to actuate a costas loop 200. During the time when the costas loop 200 is tracing, the tracing is capable for a carrier component of a high frequency. |
