| 摘要 |
PURPOSE:To surely acquire a PN code regardless of using a clock equal to a chip frequency by giving two clocks whose chip frequency is equal to the chip frequency and whose phase is deviated by 180 deg. alternately to each correlation device so as to acquire the PN code. CONSTITUTION:A clock with a frequency equal to the chip frequency generated by a clock generator 12 is subjected to change in phase by 180 deg. by an inversion circuit 13. Then either of the two clocks with different phase is selected by a selection circuit 14 and given to correlation devices A, B. The selection circuit 14 is switched by a timer 15 every prescribed time, and the two clocks with a different phase are inputted alternately to the correlation devices A, B every prescribed time. Thus, even if the PN code is not acquired in one clock state. the acquisition of the PN code is surely finished in the other clock state. |
