METHOD AND DEMODULATION APPARATUS FOR UPDATING SOFT INFORMATION

摘要

Disclosed are a method and the demodulation apparatus for soft information updating, applied to soft output Viterbi algorithm method, comprising: categorizing all the state transitions from a previous time point to a current time point into two sets; taking the state transition set triggered by input information bit value 0 as a first state transition set; taking the state transition set triggered by input information bit value 1 as a second state transition set; and taking the difference between the minimum accumulated metric selected from the first state transition set and the minimum accumulated metric selected from the second state transition set as the soft information value at the current time point. The present invention improves upon the soft information algorithm for SOVA-1, only storing one soft information value at each time point. When compared to SOVA-1 which stores one soft information value for every state at each time point, the present invention greatly conserves storage space and requires no traceback. While maintaining the same low computational complexity as the original SOVA-1 algorithm, the present invention increases the reliability of the soft information, sending the soft information to the decoder, and thus improves the decoding performance of the decoder.