The packet interleaving method includes selecting successive input sets of consecutive input packets (X1 . . . XNin) received from a forward correction module (14), each input packet (Xj) being a vector of constellation points of a predetermined constellation diagram. For each input set, it further includes generating an output set of output packets (O1 . . . ONout), each output packet (Om) being a vector of constellation points, by distributing the constellation points of each input packet (Xj) of the input set, and sending the output packets (O1 . . . ONout) of the output set to a modulator (18). The input set including Nin input packets (X1 . . . XNin) and each of the Nin input packets (X1 . . . XNin) including a same number Lin of constellation points, the number Nout of output packets in the output set is related to Lin by the relation Lin=A×Nout, where A is a fixed whole number.