An Improvement on LDPC Coded Queued Codes

The queued-code based on low-density parity-check (LDPC) codes, which exploit both the near Shannon-limit performance LDPC codes and the instantaneous channel state information (CSI), can provide excellent performance in the block fading channels. The existing work utilized the conventional random puncturing and repetition operation, which may lead to considerable performance loss due to the changed intrinsic connections of parity-check matrix (PCM) for the receiver. In this paper, we present a reversed sequential puncturing (RSP) scheme and a construction method with modified dual-diagonal structure for the LDPC coded queued-code. The consecutive puncturing pattern in reversed direction can ensure the uniform row-weight distribution of the punctured PCM. The modified dual-diagonal form and the RSP scheme can ensure no more than one punctured symbol involved in each check-sum equation. The simulation results demonstrate that our proposed scheme can achieve noticeable performance gains.