Linearly-encodable rate-compatible punctured LDPC codes with low error floor

We propose a class of rate-compatible (RC) low-density parity-check (LDPC) codes that has linear encoding complexity and low error floor. To ensure linear encoding, a deterministic form for the parity part of the mother parity-check matrix is used. To guarantee good performances in the waterfall region for a wide range of code rates, a layered density evolution algorithm is developed to obtain the degree distributions. Then, a layered node-connection algorithm is proposed to lower the error floor by increasing the values of extrinsic-message degrees of the codes. Simulation results show that no error floor is observed at a frame error rate of 10^-5 for the proposed RC code.