Design of Nonbinary Rate-Compatible LDPC Codes Utilizing Bit-Wise Shortening Method

Based on the algebraic properties of binary images corresponding to the nonbinary elements, we propose a construction of nonbinary rate-compatible low-density parity-check (RC-LDPC) codes at short block length by using bit-wise shortening method. Different from the traditional information-shortening methods, the shortened information bits in the proposed method are carefully chosen according to the degree distributions of their binary images. Simulations show that the performance of proposed method is close to that of uniform bit-wise shortening, and considerable gains can be attained over conventional symbol-wise shortening, random bit-wise shortening and their corresponding binary RC-LDPC codes.