An encoding method generates a parity bit sequence by encoding an information sequence with feed-forward LDPC convolutional codes based on a plurality of parity check polynomials each having a coding rate of (n−1)/n, then performs an interleaving process and an accumulation process. The accumulation process is an exclusive OR operation performed on bits of the interleaved parity bit sequence and on bits of a delayed accumulated parity bit sequence. A coded sequence is then generated from the information sequence and the accumulated parity bit sequence.