  We study low-complexity iterative decoding algorithms for product codes. We
revisit two algorithms recently proposed by the authors based on bounded
distance decoding (BDD) of the component codes that improve the performance of
conventional iterative BDD (iBDD). We then propose a novel decoding algorithm
that is based on generalized minimum distance decoding of the component codes.
The proposed algorithm closes over 50% of the performance gap between iBDD and
turbo product decoding (TPD) based on the Chase-Pyndiah algorithm. Moreover,
the algorithm only leads to a limited increase in complexity with respect to
iBDD and has significantly lower complexity than TPD. The studied algorithms
are particularly interesting for high-throughput fiber-optic communications.
