Design of rate-compatible RA-type low-density parity-check codes using splitting

In this letter, a new rate-control scheme, called splitting, is proposed to construct low-rate codes from high-rate codes, which splits rows of parity-check matrices of repeat accumulate-type (RA-Type) LDPC codes by adding new parity bits. When a high-degree check node is split into two low-degree check nodes, by making the check node degree distribution in a concentrated form, the performance of low-rate codes can be improved. We also explicitly construct rate-compatible repeat RA-Type LDPC (RC RA-type LDPC) codes using splitting for code rates from 1/3 to 4/5 and compare this with other RC RA-type LDPC codes.