论文部分内容阅读
为了降低编码的复杂度,基于组合数学的方法构造出一类高码率低密度校验(LDPC)码短码。该方法由循环差族构造出一类参数λ为1的平衡非完全块设计(BIBD),再基于这些BIBD构造LDPC码。构造出的LDPC码具有准循环特性,因此编码复杂度低。码字的Tanner图中没有长度为4的环路,在采用置信度传播译码时具有很好的译码性能。仿真结果表明:基于循环差族构造出的LDPC码具有与随机构造的LDPC码相当的性能。构造出的码字适用于手持数字视频广播系统。
In order to reduce the complexity of encoding, a class of high code rate low density parity check (LDPC) code short codes are constructed based on combinatorial mathematics. In this method, a class of balanced incomplete block design (BIBD) with parameter λ of 1 is constructed by cyclic difference family, and then LDPC codes are constructed based on these BIBD. The constructed LDPC codes have quasi-cyclic characteristics, so the coding complexity is low. There is no loop of length 4 in the Tanner graph of codewords, which has good decoding performance when using belief propagation decoding. The simulation results show that the LDPC codes constructed based on cyclic difference families have the same performance as the randomly constructed LDPC codes. The constructed codewords are suitable for handheld digital video broadcasting system.