Radio communication system, radio transmission apparatus and radio reception apparatus

A radio communication system comprising:

• a radio transmitter comprising:
• a division unit configured to divide transmission data into a plurality of first code blocks each having N-bit data (N is an integer of not less than 1);
• an addition unit configured to add a plurality of error detection codes to the first code blocks, respectively;
• an assignment unit configured to assign the first code blocks to a plurality of second code blocks each including M (M is an integer of not less than 1 and not more than a carrier count) carriers each having L (L is an integer of not less than 1) symbols;
• and
• a transmission unit configured to transmit the second code blocks to which the first code blocks are assigned;
• and
• a radio receiver comprising:
• a reception unit configured to receive the second code blocks transmitted by the transmission unit;
• a conversion unit configured to convert the received second code blocks into the first code blocks to which the error detection codes are added, based on first values of M and L;
• a correction decoding unit configured to subject the first coded blocks obtained by the conversion unit to error correction decoding;
• a detection unit configured to detect an errors of at least one code block of the first code blocks subjected to the error correction decoding;
• a generation unit configured to generate a retransmission request signal for requesting a retransmission of the code block including the error, if the error is detected by the detection unit;
• and
• a transmission unit configured to transmit the retransmission request signal;
• and
• the radio transmitter further comprising:
• a reception unit configured to receive the retransmission request signal from the radio receiver;
• a calculation unit configured to calculate an error rate indicating an error detection degree in the code block in correspondence with the first values of M and L based on the retransmission request signal;
• an error rate storage unit configured to store the error rate in correspondence with the first values of M and L;
• and
• a change unit configured to change the first values of M and L to second values of M and L corresponding to the code block with an error rate lower than the error rate corresponding to the first values of M and L, with reference to the stored error rate.

A radio reception apparatus comprising:

• a reception unit configured to receive a plurality of first code blocks each including M (M is an integer of not less than 1 and not more than a carrier count) carriers each having L (L is an integer of not less than 1) symbols;
• a conversion unit configured to convert the received first code blocks into a plurality of second code blocks each having N-bit data (N is an integer of not less than 1)to which the error detection codes are added, based on values of M and L;
• a correction decoding unit configured to subject the second coded blocks obtained by the conversion unit to error correction decoding;
• a detection unit configured to detect an error of at least one code block of the first code blocks subjected to the error correction decoding;
• and
• a generation unit configured to generate a retransmission request signal for requesting a retransmission of the code block including the error, if the error is detected by the detection unit.