A type-2 hybrid ARQ data communication device having an improved quality of transmitted data while an increase of power consumption is avoided. The communication device transmits the same information bits (S) plural times (N times) and controls (changes) the transmission power of each transmission packet so that the sum of the transmission power needed for N transmissions of the same information bits may be constant, for example, the transmission power (b) of one packet of the information bits at each transmission may be one N-th (1/N) of the transmission power (a) of one normal packet (b=a/N).