| 摘要 |
PURPOSE:To eliminate the influence of Doppler effect effectively and improve resistance to disturbance by transmitting spectrum-diffused pulses with a transmission time width that which does not exert the influence of a Doppler shift substantially. CONSTITUTION:A two-phase PSK modulating circuit 15 inputs an M-sequence code in a predetermined random time series from a PN code generator 16 through an output line 161 and adds phase keying by two-phase PSK to the output of a balanced modulator 13 corresponding to variation of the M-sequence code by an incorporated balanced modulator, etc., to perform what is called direct spectrum diffusing modulation. When autocorrelation is performed by the transmit pulses, the reception level of every chip by direct spectrum diffusing modulation in transmit pulses is all integrated, pulse by pulse, into the position of the chip when delay time is zero; and the obtained correlative peak output value is sent out to a phase detector 30 through an output line 271. |
