Code design and performance analysis using a 2-level generalized Tanner graph on the binary erasure channel

In this work, we consider code design and performance analysis using a 2-level generalized Tanner graph on the binary erasure channel. The 2-level generalized Tanner graph is composed of traditional variables nodes on the left side and generalized check nodes on the right side. The generalized check nodes are (d_c, d_c - 2), d_c ges 3, binary linear codes. Iterative decoding is applied to the 2-level generalized Tanner graph using maximum a posteriori (MAP) erasure correction in the generalized check nodes. With MAP erasure correction, each check node decoder removes as much erasures as possible, even if it cannot resolve all erasures. Code design is done using density evolution, and we will show that the proposed scheme achieves both a better design rate and lower decoding complexity compared to the traditional scheme with only single parity-check nodes.