Improvement of the Bit Duplication Method for Rate-Compatible Low-Density Parity-Check Codes

In this paper, we propose a principle for improving the “bit duplication” method for designing rate-compatible low-density parity-check (LDPC) codes. An experiment was carried out in the Matlab to obtain codes of rate-1/4 with different variants for duplicating bits from the original irregular DVB-S2 code of rate-1/2. Experimental results show that different bit duplication variants give different performance, moreover, codes using duplication of that part of the code word, where, respectively, the columns of the check matrix have the majority of the nonzero elements, turn out to be the best.