A transmission apparatus includes a first encoding unit configured to generate a new packet from a new portion obtained from a block generated from information bits, to generate a retransmission packet from a retransmission portion obtained from a block generated from information bits and held for a retransmission, and to assign the new packet and the retransmission packet to a communication channel respectively, a second encoding unit configured to assign, to a communication channel, a packet obtained by mixing the new portion and the retransmission portion, a encoding method switching unit configured to switch between operations of the first and second encoding unit, so that communication channel data output from the first or second encoding unit is transmitted, and a transmission control unit configured to control the encoding method switching unit based on information indicating a communication quality of the communication channel in a reception apparatus.