Provided is a transmission device which improves the error rate characteristic upon decoding when performing error correction encoding by using a self-orthogonal code or an LDPC-CC in a communication system using a communication path having a fading fluctuation, multi-value modulation, or MIMO transmission. In the transmission device, the self-orthogonal encoding unit (110) encodes a self-orthogonal code having a constriction length K and an interleave unit (130) rearranges a code word sequence so that the same modulation symbol includes an information bit of a moment i and a non-correlated bit of the information bit of the moment i in a multi-value modulation unit (150).