Wireless Communication System, Wireless Communication Device and Wireless Communication Method

A wireless communication device for sending back, to a transmission side that transmitted a packet signal generated by encoding a bit sequence to be transmitted, ACK to indicate that the packet signal has been received normally or NACK to indicate that the packet signal could not be received normally in response to the reception of the packet signal, characterized in that

• said transmission side operates exclusive-or on the bit sequence concerning the packet signals for which NACK has been sent back in a case where a number of these packet signals has reached a predetermined number, which is two or greater, and transmits an auxiliary packet signal generated by encoding the bit sequence resulting from the operation,
• said wireless communication device comprises:
• a likelihood calculation unit that calculates a likelihood information on a received packet signal;
• a received packet information storage unit that stores the likelihood information on the packet signal for which NACK has been sent back;
• and
• a decoding unit that decodes the auxiliary packet signal and the predetermined number of packet signals for which NACK has been sent back on a basis of the likelihood information on the auxiliary packet signal and the likelihood information on the predetermined number of packet signals stored in said received packet information storing unit in a case where the auxiliary packet signal has been received, and
• said decoding unit carries out a decoding process that corresponds to the encoding on each piece of the likelihood information on the auxiliary packet signal and the predetermined number of packet signals for which NACK has been sent back, updates each piece of the likelihood information after the decoding process on a basis of a mutual information of the corresponding packet signals, carries out an operation that corresponds to exclusive-or by said transmission side on each piece of the likelihood information after being updated, and reflects each piece of the likelihood information resulting from the operation in the decoding process concerning the corresponding packet signals.

A wireless communication method according to which a wireless communication device that has received a packet signal generated by encoding a bit sequence to be transmitted sends back, to a transmission side that transmitted the packet signal, ACK to indicate that the packet signal has been received normally or NACK to indicate that the packet signal could not be received normally, characterized in that

• said transmission side operates exclusive-or on the bit sequence concerning the packet signals for which NACK has been sent back in a case where a number of these packet signals has reached a predetermined number, which is two or greater, and transmits an auxiliary packet signal generated by encoding the bit sequence resulting from the operation,
• said wireless communication device carries out:
• a likelihood calculation step of calculating a likelihood information on the received packet signal;
• a received packet information storing step of storing in a memory the likelihood information on the packet signal for which NACK has been sent back;
• and
• a decoding step of decoding the auxiliary packet signal and the predetermined number of packet signals for which NACK has been sent back on a basis of the likelihood information on the auxiliary packet signal and the likelihood information on the predetermined number of packet signals for which NACK has been sent back in a case where the auxiliary packet signal has been received, wherein
• in said decoding step, a decoding process that corresponds to the encoding is carried out on each piece of the likelihood information on the auxiliary packet signal and the predetermined number of packet signals for which NACK has been sent back, each piece of the likelihood information after the decoding process is updated on a basis of a mutual information of the corresponding packet signals, an operation that corresponds to exclusive-or by said transmission side is carried out on each piece of the likelihood information after being updated, and each piece of the likelihood information resulting from the operation is reflected in the decoding process concerning the corresponding packet signals.