| 摘要 |
PURPOSE:To reduce power consumption for a long time use of the telephone set and to exclude adverse effect on other equipment by sequentially increasing a transmission output from a low output till a link is set up between a master set connecting to a telephone line and a slave set executing the communication by the spread spectrum system. CONSTITUTION:An analog voice signal 110 received from a microphone 101 is given to a CODEC 103, in which the signal is converted into a digital signal 104. The signal 104 is given to a spread spectrum/inverse spread section 106, where spread spectrum modulation is implemented based on a command signal 112 from a control section 108 and a control section 115 is given to a variable amplifier 107. On the other hand, a control signal 113 from the control section 108 is given to a D/A converter 109, which converts the signal 113 into a DC voltage signal 114 used to decide a gain of the amplifier 107 and a transmission output level for the signal 115 is decided based thereon. A signal 105 received from an antenna 100 is subject to inverse spread modulation based on the signal 112 and the modulated signal is converted into an analog voice signal 111, which is outputted from a speaker 102. |
