To provide a radio communication system for performing appropriate radio communication while reducing power consumption.

A transmitter 1 reads a transmission object data from an information source 11, and a modulating part 12 and a pulse generating part 13 generate a modulated pulse. The generated pulse is transmitted to a receiver 2 through a transmitting antenna 14. Meanwhile, when the receiver 2 receives the pulse transmitted from the transmitter 1 through a receiving antenna 21, the receiver 2 converts the received pulse into a pulse waveform of a voltage doubler in a demodulating part 22. That is, a voltage doubler circuit 22a stores the voltage of the negative component of the pulse, adds voltage of the positive component and outputs the added voltage. Then, the receiver 2 integrates the converted pulse waveform in the demodulating part 22, compares an integration result with a threshold and demodulates (restores) the data.