| 摘要 |
<p>PURPOSE:To prevent the reduction in the demodulation capability even when a reception signal is weak by demodulating the reception signal in response to a 2nd reference clock generated independently of the correlation between the reception signal and a reference signal. CONSTITUTION:The receiver is provided with an oscillator 1 generating a clock, a clock changeover circuit 2 selecting the clock from the oscillator 1 and a clock obtained from a convolution output, a clock recovery circuit 3, a frequency divider circuit 4, a spread code generator 5, a surface acoustic wave convolution device (SAW convolver) 6 to take the correlation, an envelope detector 7, a peak detection circuit 8, a local oscillator 10, a timing extraction circuit 11 and mixers 20, 30. when the reception signal is interrupted, the demodulation continues in response to the 2nd reference clock generated independently of the correlation output. Thus, even when the transmission information is interrupted, the synchronization is not required to be acquired again.</p> |
