| 摘要 |
PURPOSE:To control the information desired not to be known by an unpermitted receiver especially at a base station by adding a scramble circuit and its control section to the base station, and a descramble circuit to a receiver. CONSTITUTION:A signal transmitted from a telephone set 1 is converted into a code by a control section 3 through an exchange 2, modulated by a modulation section 4, and transmitted via a transmission section 5 and an antenna 6. The control section 3 applies scrambling to its code. The signal transmitted from the base station is demodulated by a demodulation section 9 via a reception section 8 from an antenna 7, one is inputted to a decoder 12 via a gate 11, and the other is inputted to the decoder 12 via the gate 11 from the descramble circuit 10. The descramble circuit 10 acts like restoring the scrambled code by the control section 3 of the base station. When a signal C is inputted to the decoder 12, it is compared with a call number stored in the ROM13 in advance and when they are coincident, a speaker 17 is energized and an information code succeeding to the call number is displayed on a display device 14. |
