| 摘要 |
PURPOSE:To take synchronization of a PN(pseudo noise) code surely at a high speed by monitoring a level of a reception signal after the PN code is multiplied with a partial correlation between the PN code of the reception signal and a PN code of the receiver. CONSTITUTION:A correlation device 2 takes partial correlation of a PN code of a receiver side and a peak detector 3 detects q peak of autocorrelation. The correlation arithmetic operation is executed for one over several number of the total length of a PN code. Then the peak detector 3 checks an input level of a level discrimination device 6 when the peak detector 3 detects a peak of the partial correlation. Since inverse spread is executed when the PN code is acquired, the level exceeds a threshold level. However, since no inverse spread is executed when the peak of the autocorrelation results from the pseudo acquisition, the level does not exceed the threshold level. Thus, the PN code is surely acquired without pseudo acquisition. |
