Embedded state metric storage used in MAP decoder implementation

摘要

A method，embedded state metric storage，is used for MAP decoder of turbo codes to reduce the memory requirement of state metrics information calculation．For log MAP decoder，this method includes Selecting all embedded metrics from the updated state metric in each direction，forward and reverse，and subtracting the embedded metric from the state metrics．The contribution of an embedded metric during state metric updating and likelihood ratio calculation is embedded in the relationship among the state metrics．Thus，the embedded metric need not be kept in the state metrics memory，and calculation using the embedded metric call be omitted Therefore，the latency and area in the implementation will be reduced with embedded state metric storage．