次最优软输出算法的高效存储策略

Memory-efficient arrangement scheme for sub-optimal MAP algorithm

具有优秀误码性能的迭代接收机在实现中面临的一个关键问题就是译码算法对内存的过大需求。滑动窗法可以有效地减少内存以及处理时延。利用算法递归值的单次可利用性,进一步优化该法:通过对网格中状态度量进行实时的释放与更新,使内存消耗又缩减一倍;通过将似然比计算嵌入到双向递归的过程,使处理时延只为传统窗法的1/3;通过保留两个后向递归器结构,经实验表明接收机在优化实现后整体误码性能不减。

The itcrative receivers perform an outstanding reliable transmission at very low signal-to-noise ratio.However,the practical implementation of these is a very challenging topic,partly due to memory intensive.The approach of sliding window is used to reduce memory and delay.Applied the independent recursive nature of iterative decoding,this paper devotes an optimized arrangement scheme：the real-time release and update are proposed to reduce the memory consumption to 50%,the design of the computation for LLR without waiting is considered for reducing the delay to 33%,and there are still two backward recursion for remaining high perfomlance.Simulation results support all above in the end.