APPARATUS AND METHOD FOR EXTRACTING BINARY ALGEBRA LIKELIHOOD RATIO FOR USING BINARY TURBO DECODER WHEN MULTI-MODULATION SYMBOL PASSES MULTI-PATH FADING CHANNEL

摘要

PURPOSE: An apparatus and method for extracting a binary algebra likelihood ratio for using a binary turbo decoder when a multi-modulation symbol passes a multi-path fading channel are provided to heighten a coefficient of utilization and shorten transmission time of data communication without any change to a binary turbo decoder. CONSTITUTION: Outputs of an equalizer are in parallel inputted to a Symbol to Bit Module(300). The inputted values are split to come to blocks(310) corresponding to each construction bit. The input value inputted to the block of each bit is identical to an equalizer output value. A Bit Division Module(320) classifies the input values coming in parallel thereto by ith construction bit '0' and ith construction bit '1' and inputs them to a Max Module(330). The Max Module(330) obtains the maximum value among the input values and obtains two algebra probability values for the ith construction bit. Then, a subtractor(340) subtracts the two algebra probability values and obtains a value. This value is a log likelihood value for the input value corresponding to the ith bit among 'm' number of coded bits inputted into a signal mapper.