| 摘要 |
PROBLEM TO BE SOLVED: To secure carrier synchronization while suppressing average transmission power in transmitting a transmission frame. SOLUTION: A radio information communication device 10 performs specified coding to form transmission data, and adds a preamble part consisting of a BPSK modulation signal to it so as to form a transmission frame. If communication state is good when transmitting the preamble part, it selects the voltage of a normal voltage generator 36 by a switching circuit 38 and supplies it to the power amplifier 35 of a transmission circuit 25, thereby controlling transmission power into a state equal to that of a data. If the communication state is bad, it selects the voltage of a preamble voltage generator 37 by a switching circuit 38 and supplies it to the power amplifier 35, thereby raising the transmission power higher than that of the data. |
