FIELD: physics; communication.
SUBSTANCE: invention relates to mobile communication engineering. On the condition that when there are no messages which should be sent to a mobile transmitting/receiving device, the modulation non-availability carrier signal is output in the transport data control information region, having a certain frame structure. The modulator induces the transmission circuit to output the modulation non-availability carrier signal from the line control device in accordance with the control information region in which modulation non-availability data are installed through a frame data processing device, while a modulated wave signal is generated as a four-level modulates signal and is output in regions other than the modulation non-availability data region. When modulation non-availability data are installed in the control information region, functional channel identification information in the same frame is installed as modulation non-availability identification data, thereby avoiding any unstable operation in a mobile transmission/reception device at the receiving end.
EFFECT: communication channel bandwidth reduction and reduced effect on adjacent channels.
6 cl, 11 dwg
