| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably acquire synchronization even under an environment where a frequency offset and noise coexist. SOLUTION: In a synchronization circuit 100, received signals from an antenna are converted to base band signals in a local oscillator 1 and an LPF 2 and sampled in an S/H 3, a correlation value for which the spread code of the received signals and the symbol are multiplied is obtained in a correlation device 4 and a power value for which the plural symbols are added is obtained while inversely modulating the correlation value and correcting phase rotation by the frequency offset based on the theoretical value of the symbol corresponding to the correlation value or a judgment value after demodulation in a symbol integrator 5. A path search part 10 adds the power value for plural slots and a demodulation path selection part 12 selects a reception timing from the ones for which power added values inputted from the path search part 10 are selected in a descending order and outputs it. A frequency offset estimation part 11 selects a valid path from the correlation value outputted by the correlation device 4 by using demodulation path timing information obtained from the demodulation path selection part 12, estimates the frequency offset and supplies it to the symbol integrator 5.</p> |
