Retransmission control method

A retransmission control method for a radio communication system including a first radio station and a second radio station, the retransmission control method comprising:

• at the first radio station,
• transmitting user data via radio to the second radio station, the user data being accommodated in a radio packet for user data;
• and
• in response to a retransmission request from the second radio station retransmitting the radio packet for user data;
• and
• at the second radio station,
• receiving, via radio, the radio packet for user data transmitted in the transmitting or the retransmitting;
• performing first signal detection processing on a radio signal received in the receiving;
• performing first code error detection processing on the radio packet for user data detected in the first signal detection processing;
• in a case in which a code error is detected in the first code error detection, making a retransmission request for the radio packet for user data to the first radio station;
• in a case in which a code error is not detected in the first code error detection, performing first enqueuing of the radio packet for user data in a reception buffer;
• performing second signal detection processing on the radio signal received in the receiving with a longer processing delay than a processing delay of the first signal detection processing, wherein the second radio station performs the second signal detection processing in parallel with the first signal detection processing;
• performing second code error detection processing on the radio packet for user data detected in the second signal detection processing;
• in a case in which a code error is not detected in the second code error detection, performing second enqueuing of the radio packet for user data in the reception buffer;
• and
• outputting, at a predetermined timing, one or more radio packets that are enqueued in the reception buffer.