说明：  LDPC研究者MacKay提供的校验矩阵H和对应的G，其中H的行重12，列重6，行数504，列数1008，任意两行不含围长为4的圈
(LDPC researchers MacKay, the calibration matrix corresponding to the H and G, in which the re-H 12, series 6, a few 504, cited 1008, the two firms were non-arbitrary girth to the ring 4)