MEMORY-EFFICIENT PATH METRIC UPDATE METHOD IN MAP DECODER IMPLEMENTATION

摘要

A novel memory efficient path metric update is proposed for Maximum A Posteriori(MAP)decoder of turbo codes to reduce the memory requirement of state metric information calcalation.For MAP decoder,the same memory can be shared by the forward and backward metricswith this metric update scheme.The forward and backward metrics update can be performed atthe same time.And a11 of the extrinsic information can be calculated at the end of metric update.Therefore,the latency and area in the implementation will be reduced with the proposed metricupdate method.