Spatially coupled LDPC codes for two-user decode-and-forward relaying

Stefan Schwandter, Alexandre Graell i Amat, Gerald Matz

Abstract: We present a decode-and-forward transmission scheme that is based on spatially coupled LDPC codes and applies to a network consisting of two sources, one relay, and one destination. The relay performs network coding to achieve full diversity. We prove analytically that the proposed scheme achieves the Shannon limit on the binary erasure relay channel for symmetric channel conditions. Using density evolution, we furthermore demonstrate that our scheme approaches capacity also for asymmetric channel conditions.