Abstract:Low-Density Parity-Check(LDPC) codes are first introduced by Gallagerin 1960's,and independently rediscovered by both MacKay and Neal. In past few years, LDPC codes have received a lot of attention and many new developments have been brought in this area. This paper has designed a class of Low Density Parity Check(LDPC)codes based on ITU. Our design is for 6-bit quantizaton with a code rate of 0.7572 and a block size of 276 bits. This paper brings forward the architecture of the partly parallel decoder and the corresponding parallel encoder based on CPLD technology. Also we have derived the encoder scheme. And this LDPC code is used for ADSL transmission.