| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a correlation synchronizing circuit to generate a synchronization signal to obtain a stable correlation signal, even when the correlation signal is multiplexed in a direct spread spectrum communication system. SOLUTION: A correlation output signal, whose square-sum-square root to be inputted is calculated, is compared with a specified threshold value by a discriminator 1, when output exceeding no threshold value are continuously outputted twice, a signal is transferred in a timing of the output, and the signal is outputted one-time in a spread cycle (a multiplexed block) by a processing part 4. The fact that signals from a processing part 4 are continuously outputted with the same timing several times is confirmed, and synchronization is established by an initial synchronization circuit 2. A pulse is generated with a timing in which the next correlation output is not outputted consecutively twice (once in a multiplexed block), so that the established timing is held by a synchronization counter 3. The output of the synchronization counter 3 is compared with the output of the processing part 4 by a decision part 5 and correlation synchronization is held by counting up a correct lock counter, when the timing coincides and counting up an erroneous lock counter 6 when no timing coincides.</p> |
