| 摘要 |
PURPOSE:To fix a voltage controlled oscillator to a prescribed voltage and to quicken the synchronization locking by bringing the state to a synchronizing loop control range deviation state when any of a correlation between a reception signal and two adjacent receiver PN code series is a prescribed threshold level or below. CONSTITUTION:A transmission data modulated by a PN code series (CS) is used as a reception signal Sr, a correlation between a receiver side code equal to the series CS and the signal Sr is obtained by two multiplier sections 1, 2 and envelope detectors 3, 4. Correlation outputs (1), (2) of the detectors 3, 4 are fed to a subtractor 6 and a phase comparator section 9 and when any of the outputs (1), (2) reaches a threshold level being zero and an offset or below, the state is discriminated to be a synchronizing loop control range deviation state, and a selector 10 selects a prescribed voltage +V controlling a voltage controlled oscillator VCO 7 in place of an output of a loop filter 6. Thus, the synchronization locking is quickened without deviating the control range of the delay synchronizing loop. |
