A radio communication apparatus of the present invention aims at improving an error rate characteristic in the end receiver. A repeater (radio relay device) RS2 receives a signal transmitted from a repeater RS1 at a point of time of signal transmission from the repeater RS1, and detects whether or not an error exists in the signal at a point of time of transmission. Also, when the repeater RS2 detects the error from a systematic bit S of the transmitted signal from the repeater RS1, such repeater RS2 generates error position information EI, replace a part of a parity bit P with the error position information EI, and transmits a resultant signal. The error detection result is notified through the control channel. The mobile station (mobile terminal) MS makes an error correction based on the error position information EI, and demodulates the signal by executing an error correction decoding process.