CAJ | 학술논문

提出一种能够匹配多媒体业务特性的独立窗口 LT 码（independent window LT，IW-LT）不等差错保护方案，采用无码率 LT 码对不同重要等级的数据分别进行独立选窗和编码。通过与或树分析法推导了 IW-LT 码的渐近译码性能，并结合多目标进化算法联合优化编码度分布和选窗概率，以精确匹配预设的不等保护增益及译码开销，增加了不等差错保护方案的灵活性。仿真证明，IW-LT 码与现有的无码率码不等差错保护方案相比，能在精确匹配不等差错性能参数的前提下，获得更低的译码差错概率。
제출일충능구필배다매체업무특성적독립창구 LT 마（independent window LT，IW-LT）불등차착보호방안，채용무마솔 LT 마대불동중요등급적수거분별진행독립선창화편마。통과여혹수분석법추도료 IW-LT 마적점근역마성능，병결합다목표진화산법연합우화편마도분포화선창개솔，이정학필배예설적불등보호증익급역마개소，증가료불등차착보호방안적령활성。방진증명，IW-LT 마여현유적무마솔마불등차착보호방안상비，능재정학필배불등차착성능삼수적전제하，획득경저적역마차착개솔。
To match the multimedia service transmission,an unequal error protection (UEP)scheme based on the independent window LT (IW-LT)code is proposed.According to the level of importance,the original data are divided into independent windows and encoded by rateless LT codes.The asymptotic decoding perform-ance of IW-LT codes is derived by the AND-OR tree analysis technique.Moreover,to accurately match the ex-pected UEP gain and decoding overhead,multi-objective genetic algorithms are introduced to optimize the degree distribution and probabilities of selecting windows,which enhance the flexibility of the IW-LT UEP scheme. The simulation results show that,compared with the existing rateless coding UEP scheme,IW-LT codes can obtain a lower decoding error rate under the fixed parameters of UEP property.