| 摘要 |
PURPOSE:To synchronize a pseudo noise code at a reception side with a pseudo noise code at a transmission side even if communication is tentatively interrupted or electric field intensity is lowered by controlling a clock given to a spread spectrum demodulation pseudo noise code in response to stored synchronization tracing information when the synchronizing step-out is detected during the synchronization tracing. CONSTITUTION:While a synchronous signal (q) is outputted from a Schmitt circuit 30, synchronization tracing is applied and synchronization tracing information (r) is always stored in a memory means 53 in response to the period of the latest synchronization tracing phase shift signal (p) and the direction of phase shift. When communication is interrupted or the spread spectrum signal is not received with a sufficient electric field intensity due to fading, the synchronous signal (q) outputted from the Schmitt circuit 30 is lost. The synchronization tracing information (r) is read from the memory means 53 to a clock phase shift controller 41, preset in a phase shift counting means, a reference clock (o) is counted down and a carrier-out output is outputted when the clock is zero. Thus, the deviation of phase of the pseudo noise code at a reception side is corrected with respect to a pseudo noise code at a transmission side. |
