| 摘要 |
<p>PROBLEM TO BE SOLVED: To accurately detect synchronous time by the synchronizing device of a CDMA receiver even if a precedent wave and a delayed wave overlap with each other to cause the level of the correlative value of a receive signal to vary or shift in peak position. SOLUTION: A correlating circuit 120 calculates the correlative value between the receive signal and a known pattern. A reception timing detecting circuit 130 differentiates the correlative value with time to find the maximum value of the differentiated value. A synchronous time detecting circuit 150 generates a histogram of the rate of the time when the differentiated value becomes maximum and finds synchronous time according to the time of a rate exceeding a threshold value. A synchronizing pulse output circuit 160 generates a synchronizing pulse when the synchronous time matches a counter value. A reception window control circuit 140 generates a time signal and a reception window signal to be detected synchronously. The synchronous time is detected from the time when the differentiated value of the correlative value, so even if the correlative value varies in level, the synchronous time can be accurately found.</p> |
