A radio communication system minimizes power consumption against noises. The system includes a first radio terminal (10A) with a first transmitter (40A) for transmitting a first data indicative of a specific event, and a second radio terminal (40A) with a battery (14B) and a receiver (20B). The first radio terminal (10A) includes a first bit interpolator (32A) which inserts a check bit pattern of “01010101” at a predetermined cycle into one frame of the first data. The second radio terminal (10B) has a second power controller (60B) which intermittently activates the second receiver (20B) at predetermined intervals in order to receive the bit-interpolated data from the first transmitter. A check bit detector (24B) is included in the second radio terminal (10B) to detect the check bit pattern from within the bit interpolated data and to issue a stop signal immediately upon occurrence of that the check bit pattern fails to appear at said predetermined cycle within a predetermined time frame shorter than one frame length of the first data. In response to the stop signal, the power controller of the second radio terminal terminates a current receiving operation.