Interleaver apparatus and receiver for a signal generated by the interleaver apparatus

A convolution interleaver for processing a codeword derived from an input block of symbols using a redundancy-adding coding, and having more symbols than the input block, wherein the codeword has a sequence of interleaving units, wherein each interleaving unit has at least two symbols, includes an interleaver. The interleaver changes the sequence of interleaving units to obtain an interleaved codeword having a changed sequence of interleaving units. In particular, the order of the symbols within an interleaving unit is not changed by the interleaver. The order of the interleaving units in the codeword among each other or with respect to a previous or subsequent codeword is changed, however.