说明：  Low Density Parity Check (LDPC) 信道编码的C程序。二部图连接关系的输入在20000.10000.3.631.txt 文件中。文件中的参数包括check，variable节点的度数，具体的连接关系。可根据具体需要，需改你所需的txt文件，从而实现任意参数的LDPC程序仿真。经验证，此程序的性能正确，符合理论文献中的结果。
(Low Density Parity Check (LDPC) codes simulation C program. This program is developed by Seishi Takamura in Stanford University. This program can realized the simulation of ber performance of regular LDPC codes. The code structure is defined by the*.txt file including the check node degree, variable node degree and the connection indices between the nodes in the bipartite graph. If you want to simulate LDPC codes with other parameters, you can only modify this input .txt file. I have tested this program and the logic is correct and performance is also accurate in the Bit error rate. In addition, the syntax of this program is so easy to learn. Generally speaking, it is a very good example for the rookie people working in the channel coding area.)