PURPOSE: To negate the linearity of an M series and to prevent the analogy of the M series from being performed by the malfeasant reception of a non- modulated M series by performing two times of scrambling in lateral and longitudinal directions in a telemetry frame block diagram.

CONSTITUTION: Firstly, the scrambling in the lateral direction of the telemetry block diagram is performed in a first scrambling circuit 3 by using the output of a first M series generation circuit 2. Thence, the scrambling in the longitudinal direction of the telemetry block diagram is performed in a second scrambling circuit 5 by using the output of a second M series generation circuit 4. In such a way, by performing two times of scrambling in the lateral direction (subframe direction) and the longitudinal direction (time slot direction) of the telemetry block diagram by different M series, it is possible to prevent the analogy of the M series from being performed by the malfeasant reception of the non-modulated M series.