Wireless communication system, wireless communication apparatus, and buffer clearing method

A relay station apparatus that performs relay and transmission between a first radio communication apparatus and a second radio communication apparatus, the relay station apparatus comprising:

• a generating section that performs error detection on first transmission data transmitted from the first radio communication apparatus and second transmission data transmitted from the second radio communication apparatus, to generate an acknowledgement signal or a negative acknowledgement signal as a response signal;
• a coding section that, when a first response signal corresponding to the first transmission data and a second response signal corresponding to the second transmission data are both acknowledgement signals, performs network coding using the first transmission data and the second transmission data to generate relay data;
• and
• a transmission section that transmits the first response signal, the second response signal and the relay data to the first radio communication apparatus and the second radio communication apparatus.

A radio communication apparatus that communicates with another radio communication apparatus, via a relay station apparatus which generates relay data by performing network coding using first transmission data transmitted from the radio communication apparatus and second transmission data transmitted from the other radio communication apparatus, the radio communication apparatus comprising:

• a buffer that stores the first transmission data;
• a reception section that receives a first response signal corresponding to the first transmission data, a second response signal corresponding to the second transmission data and the relay data;
• a determination section that determines a smaller number, as compared between a number of a first acknowledgement signals for the first transmission data and a number of second acknowledgement signals for the second transmission data;
• a removing section that removes an amount of the first transmission data equal to a difference between the number of first acknowledgement signals and the smaller number;
• and
• a decoding section that performs network decoding using the relay data and the first transmission data stored in the buffer to obtain the second transmission data.

A signal relaying method in a relay station apparatus that performs relay and transmission between a first radio communication apparatus and a second radio communication apparatus, the method comprising:

• performing error detection on first transmission data transmitted from the first radio communication apparatus and second transmission data transmitted from the second radio communication apparatus, to generate an acknowledgement signal or a negative acknowledgement signal as a response signal;
• when a first response signal corresponding to the first transmission data and a second response signal corresponding to the second transmission data are both acknowledgement signals, performing network coding using the first transmission data and the second transmission data to generate relay data;
• and
• transmitting the first response signal, the second response signal and the relay data to the first radio communication apparatus and the second radio communication apparatus.