When a channel without TXD is existed, the channel signal trains of a first system are transmitted by the channel of a second system; thereby the utility rate of frequency bands can be improved. Channel signal trains S1- Sn (signal value +-1) are generated by data generating parts (111-1 to 111-n). A channel signal train S1 is divided into signal trains P1 and P2 by a serial or parallel conversionpart (112); the branch signal train P1 is modulated by a diffuse code D1 of a diffuse modulating part (113-1); the branch signal trains P1, P2 are modulated by the diffuse code D1 of a diffuse modulating part (113-2) when the signal values of P1 and P2 are uniform and the output is changed into high resistance when the signal values of P1 and P2 are different. Accordingly, the CH1 component of acode division multiple access (CDMA) signal A output by an addition part (114) is one of the four values of +-1, +-2. The branch signal trains P1, P2 recovered by a receiving device according to the CH1 component and the channel signal train S1 is also recovered.