A Computationally Efficient Early Stopping Method for DVB-S2 LDPC Decoder

摘要

Satellite communication requires powerful forward error correction scheme because of long transmission delay. Thus, the low density parity check (LDPC) code is adopted for the forward error correction code in DVB-S2 standard. Because decoding process of LDPC code is based on the iterative soft decoding, it is critical fact for decoder to reduce the average number of iterations. Therefore we briefly introduce a conventional hard decision based early stopping method. We also introduce that the conventional early stopping method is combined with a horizontal shuffling scheduling (HSS) algorithm which is one of layered decoding scheme. However, the computational complexity of this conventional hard decision based method is still high, because this computes the early stopping criterion at the end of iterations. In this paper, we propose a computationally efficient early stopping method which computes the early stopping criterion at specific iterations. The simulation results show that the proposed early stopping method reduces the number of iterations of LDPC decoding algorithm. Furthermore, the computational complexity of proposed early stopping method is fewer than those of the conventional HD based early stopping method.