APPARATUS AND METHOD FOR SOFT DEMAPPER IN MIMO SYSTEM AND EFFECTIVE BIT CALCULATION USED THE SAME

摘要

An effective bit calculating method used with a soft-decision decoding apparatus for improving performance while reducing the implementation complexity in a multi input multi output system and a method thereof in a multi input multi output system and a method thereof are provided to maximize channel decoding performance. One or more multiplier multiplies the soft demapper signal according to a modulation mode by the size shape value of the null matrix vectors outputted from the detector. An effective bit calculator(302) deletes a part of the lower bit about the output bit of the multiplication method and extracts the effective bit. The effective bit calculating unit compares the absolute value and threshold value of the rest bit. According to the comparison result, the definite value is set up as the upper bit or rounds in the number corresponding to the specific bit.