However, the performance of LDPC code depends on the girth of its bipartite graph, that is it depends on its sparse parity-check matrices H, especially the complexity of encoding with H.
而LDPC码性能的优劣，与其二分图中是否存在短长度的圈有关，也即与其奇偶校验矩阵的构造有关。
2
Fountain code is record-breaking sparse-graph code for channels with erasures.