CAJ | 학술논문

针对正反馈存在于短帧多元低密度奇偶校验码（low density parity check，LDPC）与高阶连续相位调制（continuous phase modulation，CPM）迭代系统中的问题，提出一种在低信噪比采用加权联合平均外信息交换、在中高信噪比采用加权外信息交换的外信息处理方式。该方式对解调器与译码器之间传递的外信息进行相应处理，可以有效控制波动过大的位概率。同时将交叉熵（cross entropy，CE）和辅助硬判决（hard decision aided， HDA）两种迭代停止准则与加权外信息处理方式结合进行动态迭代译码。理论分析和仿真结果表明，对外信息交换进行加权操作并联合动态迭代停止算法能够在有效减少正反馈的同时使迭代的收敛性得到优化，同时迭代停止算法可减少平均迭代次数，提高系统的实时性。
침대정반궤존재우단정다원저밀도기우교험마（low density parity check，LDPC）여고계련속상위조제（continuous phase modulation，CPM）질대계통중적문제，제출일충재저신조비채용가권연합평균외신식교환、재중고신조비채용가권외신식교환적외신식처리방식。해방식대해조기여역마기지간전체적외신식진행상응처리，가이유효공제파동과대적위개솔。동시장교차적（cross entropy，CE）화보조경판결（hard decision aided， HDA）량충질대정지준칙여가권외신식처리방식결합진행동태질대역마。이론분석화방진결과표명，대외신식교환진행가권조작병연합동태질대정지산법능구재유효감소정반궤적동시사질대적수렴성득도우화，동시질대정지산법가감소평균질대차수，제고계통적실시성。
In order to decrease the positive feedback in the iterative detection of the short frame Q-ary low density parity check (LDPC)code and the high-order continuous phase modulation (CPM)system,the combi-nation average and weighted extrinsic information exchange for the low SNR,and the weighted extrinsic infor-mation exchange for the medium and high signal-to-noise ratio are proposed.In this information exchange,the extrinsic information between the demodulator and the decoder is correspondingly processed,which can control excessive fluctuations bit probability.Meanwhile,it performs decoding with two stopping criteria of dynamic it-erative decoding:cross entropy (CE)and hard decision aided (HDA).Theoretical analysis and simulation results show that the combination of weighted extrinsic information exchange and the dynamic iterative stopping algorithm can not only resist the positive feedback effectively,and improve the convergence of iterative detection and the system bit error rate performance,but also reduce the average number of iterations,and keep the system in real-time.