An introduction to spatially-coupled codes via practical examples

This paper uses examples to illustrate the ongoing transition in spatially-coupled coding from theory to practice. In the first example, we find that spatially-coupled codes have already been implemented by two different companies for 100 Gb/s optical communications. Both systems use variants of braided block codes, which were introduced even before the term spatial coupling. In the second example, we discuss the multiple-access channel and observe that some gains from spatial coupling were being realized in cellular base stations as early as 2007. Finally, we discuss some open questions regarding spatially-coupled codes.