| 摘要 |
PURPOSE: To reduce the power consumption for waiting to extend the life or a battery by taking out the primary modulation wave component of a received spread spectrum signal and demodulating information data based on the taken- out primary modulation wave component. CONSTITUTION: In a spread modulation part 22, a primary modulation wave S2 is inputted to a multiplier 23. The multiplier 23 multiplies a PN signal S10 of a repeat frequency generated in a PN generator 24 and the primary modulation wave S2 to subject the primary modulation wave S2 to spread spectrum modulation, and a spread spectrum wave S12 is outputted. Meanwhile, a band pass filter 32 to which a reception signal S13 received by an antenna 31 is inputted takes out the spectrum of a part of the reception signal S13 to extract one arbitrary primary modulation wave. An information demodulation part 33 subjects a time modulation wave S14 to demodulation processing and demodulates and outputs information data S10. Thus, the reception time is shortened by the synchronism acquisition time of the PN signal, and the power consumption for standby time is reduced. |
