| 摘要 |
PURPOSE:To make it extremely difficult to detect privacy information by the third party, by synchronizing a wave to be modulated whose frequency is variable by setting a parameter to output in a transmitting device, and detecting a carrier wave by setting a parameter synchronizing with the transmitting device, in a receiving device. CONSTITUTION:A parameter setting device 1 sets an oscillation start frequency f1, an oscillation end frequency f2 and a frequency variable speed (v) of a variable frequency oscillating device 2. When timing information being one of synchronizing signals outputted from a synchronizing signal generating device 8 is sent out to a receiving device, a transmitting device starts a transmission of a modulated wave (a). In the receiving device, a synchronizing signal which is radiated from the transmitting device is separated by a synchronizing signal separating device 15, information of the oscillation start frequency f1, the oscillation end frequency f2 and the frequency variable speed (v) in the synchronizing signal is inputted to a parameter setting device 13, its tuning frequency is varied by following a variation of a local oscillation frequency by a control of the parameter setting device 13, and a privacy signal by which a carrier wave is varied can be detected. |
