CAJ | 학술논문

由于在一定码率范围均能获得良好的误码性能,码率兼容打孔 LDPC(rate-compatible punctured LDPC, RCP-LDPC)码成为时变信道下优选编码方案.然而,与非打孔码相比,RCP-LDPC码的BP译码收敛速度太慢.为了提高译码收敛速度,提出一种基于打孔变量点分组优化和串行调度的 BP译码算法.根据BP译码消息的可靠度对打孔变量点进行排序和分组,使其在译码时,按可靠度由高到低的次序依次更新各组变量点消息.仿真结果表明,当最大译码迭代次数较低时,本文方法的误码性能优于BP算法和随机分组洗牌BP算法.特别是当打孔比特较多时,性能改善越明显.
유우재일정마솔범위균능획득량호적오마성능,마솔겸용타공 LDPC(rate-compatible punctured LDPC, RCP-LDPC)마성위시변신도하우선편마방안.연이,여비타공마상비,RCP-LDPC마적BP역마수렴속도태만.위료제고역마수렴속도,제출일충기우타공변량점분조우화화천행조도적 BP역마산법.근거BP역마소식적가고도대타공변량점진행배서화분조,사기재역마시,안가고도유고도저적차서의차경신각조변량점소식.방진결과표명,당최대역마질대차수교저시,본문방법적오마성능우우BP산법화수궤분조세패BP산법.특별시당타공비특교다시,성능개선월명현.
Rate-compatible punctured LDPC (RCP-LDPC) codes become the priority coding scheme in time-varying channels because of their good performance over a wide variety of code rates. However it has been reported that the belief propagation (BP) decoding for these codes converges slower than that for un-punctured codes. A modified BP algorithm is proposed to accelerate the decoding convergence of the RCP-LDPC codes by a sequential scheduling of punctured variable nodes updates. A sorting algorithm on message reliability of punctured variable nodes is adopted to group the punctured variable nodes. The group with higher reliability is priority scheduled when decoding, then the remaining groups are sequentially processed. The simulation results show that the proposed method outperforms both traditional and random grouping BP algorithm. Performance improvements become more distinctive as the number of punctured bits increase.