Constrained Interleaving of Serially Concatenated Codes with Inner Recursive Codes

This is the authors' abstract. We don't add key points for this paper.

A novel constrained interleaving technique is proposed to improve serially concatenated codes (SCCs) with inner recursive convolutional codes (IRCCs). In this study, constrained interleavers are designed to achieve a minimum Hamming distance (MHD) for the SCC, dSCC, between dodiand do2diwhile simultaneously maximizing the interleaver gain, where doand diare the MHD of the outer and inner codes respectively. Constrained interleavers can be constructed to achieve dSCC=dodiwhile almost maintaining the interleaver gain of uniform interleaving. By imposing additional inter-row constraints, dSCCof constrained interleaving is increased beyond dodiup to do2di, however, at the expense of some interleaver gain. Numerical results demonstrate that constrained interleaving is an efficient way to construct SCCs with low error floors while achieving interleaver gain at relatively short interleaver sizes.