| 摘要 |
PURPOSE:To improve the tracking accuracy by using a signal obtained by multiplying a window function decided in the changing direction of a frequency hopping pattern with a phase error Noise as an APC control signal. CONSTITUTION:A phase error noise by the difference between a carrier angular frequency and an oscillated angular frequency of a VCO113 has same probability for its polarity. In extracting a lead or lag element from the phase error noise, a window function decided by the frequency hopping pattern is multiplied with the phase error noise. That is, the window of +1 is multiplied to the phase error noise where the hopping changes in increasing direction and a window of-1 is multiplied with the phase error noise where the hopping changes in decreasing direction and the phase error noise is used as an APC control signal. The phase error noise appears at the output of a multiplier 12 and is inputted to a processor 14. A control section 17 decides the direction of hopping depending on the data of the PN generator 19, the processor 14 generates the window so as to generate the APC control signal, which changes the self-running angular frequency of the VCXO of the VCXO PLL 16 so as to control the phase. |
