中文说明：在信息论中，低密度奇偶校验（LDPC）码是一种线性纠错码，是在有噪声的传输信道上传输信息的一种方法，它是用稀疏二部图构造的。LDPC码是容量逼近码，这意味着对于对称无记忆信道，存在允许噪声阈值设置非常接近（甚至在BEC上任意接近）理论最大值（Shannon极限）的实际结构。噪声阈值定义了信道噪声的上界，在该上界之下，信息丢失的概率可以尽可能小。利用迭代信度传播技术，LDPC码可以在时间上按照其块长进行线性解码。
English Description：
n information theory, a low-density parity-check (LDPC) code is a linear error correcting code, a method of transmitting a message over a noisy transmission channel, and is constructed using a sparse bipartite graph. LDPC codes are capacity-approaching codes, which means that practical constructions exist that allow the noise threshold to be set very close (or even arbitrarily close on the BEC) to the theoretical maximum (the Shannon limit) for a symmetric memoryless channel. The noise threshold defines an upper bound for the channel noise, up to which the probability of lost information can be made as small as desired. Using iterative belief propagation techniques, LDPC codes can be decoded in time linear to their block length.