Sub-Block Rearranged Staircase Codes

We propose a new family of spatially coupled product codes, called sub-block rearranged staircase (SR-staircase) codes. Each SR-staircase code block is constructed by encoding rearranged preceding code blocks, where the rearrangement involves sub-blocks decomposition and transposition. The major advantage of the proposed construction over the conventional staircase construction is that it enables to employ stronger algebraic component codes to achieve better waterfall and error floor performance with lower miscorrection probability under low-complexity iterative bounded distance decoding (iBDD) while having the same code rate and similar blocklength as the conventional staircase codes. We characterize the decoding threshold of the proposed codes under iBDD by using density evolution and also derive the conditions under which they achieve a better decoding threshold than that of the conventional staircase codes. Further, we investigate the error floor performance by analyzing the contributing error patterns and their multiplicities. Both theoretical and simulation results show that SR-staircase codes outperform the conventional staircase codes in terms of waterfall and error floor while the performance can be further improved by using a large coupling width.