| 摘要 |
According to a spread spectrum communication synchronization acquisition demodulating apparatus which can acquire synchronization timing and immediately track variation of the synchronization timing irrespective of lots of noise, in a synchronizing circuit 100, a reception signal form an antenna is converted to a base band signal in a local oscillator 1 and an LPF 2, and sampled in S/H 3. In a correlator 4, the spreading code of the reception signal is multiplied by the symbol thereof to obtain a correlation value. In a symbol integrator 5, the correlation value is demodulated on the basis of the theoretical value of the symbol corresponding to the correlation value or the judgment value after demodulation, and integrated over plural symbols to obtain a power value. In a demodulation path selection unit 8, the power value from a short-time integration path search unit 6 is integrated for a short time to select higher power values in the magnification order, and the power value from a long-time integration path search unit 7 is integrated for a long time to select higher power values in the magnification order. The reception timing is selected from the power values selected in the short-time and long-time integration path search units, and the despreading is performed according to the reception timing in the correlator 9, and a composite signal is identified in a RAKE/SD unit 11 to obtain a judgment value.
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