| 摘要 |
PURPOSE:To omit the synchronization of phases of the PN codes on the reception side with the transmission side by generating a spread spectrum signal, regenerating a carrier signal demodulated by an ON/OFF keying signal from the spectrum diffusion signal, and detecting the carrier signal for output of the ON/OFF keying signal. CONSTITUTION:A gate circuit 13 applies a carrier signal received from an oscillator 14 to a spread spectrum part 15 for an ON period of an ON/OFF keying signal. A multiplier 17 multiplies the 1st PN code received from a PN code generator 16 by the output signal received from the circuit 13. Meanwhile the spread spectrum signal received via a reception antenna 21 is applied to an adverse spread spectrum on part 22. Then a multiplier 24 multiplies the 2nd PN code received from a PN code generating part 23 by the received spread spectrum signal. The output of the multiplier 24 undergoes the envelope detection via a detector 26 and through a BPF 25, and this detected output is applied to a decoder 27. Thus it is not required to secure the synchtonization of code phases on the reception side. |
