| 摘要 |
PROBLEM TO BE SOLVED: To reduce the cost by preparing plural clocks with different phases in the spread spectrum communication equipment, selecting one clock among them and providing the output of the selected clock or of an inverted selected clock so as to reduce the number of clocks. SOLUTION: A correlation detection circuit 10 detects the correlation between an intermediate frequency reception signal and a reference spread code used for inverse spread. The correlation signal is digitized by a peak detection circuit 11 and outputted to a clock generating circuit 14 and a code phase reset circuit 15. The clock generating circuit 14 selects one of N/2 signals obtained by delaying the reference clock by a delay circuit 13, a phase of a peak signal is detected, a new clock phase is calculated to generate an output clock. When the phase is a phase slower than the reference clock by a discrimination period, a phase inverting signal is outputted. A code phase reset circuit 15 provides the output of a code reset signal to take synchronization between a reference spread code and a demodulation inverse spread code. |
