Impulse noise detection techniques for retransmission to reduce delay in DSL systems

To protect digital subscriber loop (DSL) systems against impulse noise (IN), interleaving combined with Reed-Solomon (RS) coding has been used. Nevertheless, interleaving introduces a long delay. This paper considers retransmission instead of interleaving to reduce such delay and proposes an approach using the available RS decoding failure status to trigger retransmission request. Retransmission probability, average delay and bit error rate (BER) are derived and validated by simulation. Illustrative results show that retransmission can offer a much shorter delay than interleaving while efficiently avoiding transmission errors in various channel conditions.