Patent ID: 6590939
Filing Date: 2003-07-08
Classification: H03M,H04L

Abstract:
A reception method in which received symbols are functions of bits, which are detected at successive trellis levels A and B by adding to a sum of a transition metric of each path that has led to each state of level A a transition metric of a path branch, relating to a bit 1 and bit 0, that leads to the next level B and; by comparing at the level B that follows the level A the sums of the transition metrics of path branches entering each state; and by selecting, on the basis of the sums of the transition metrics, in each state of the level B the best of the two paths as a survivor path, the method comprising:generating at the level B, separately for each bit of a symbol, numbers relating to the bit 1 and bit 0 that represent a probability of the transition metrics of the survivor paths; separately summing the numbers, relating to the bit 1 and the bit 0 of more than one state, that represent the probability of the transition metric; generating logarithms of the sums; and generating a difference between the logarithms of the sums, a received signal being determined on the basis of the difference.