SOFT DECISION DEVICE AND SOFT DECISION METHOD

摘要

A soft decision device and method for obtaining a soft decision value as a value expressing a probability as near the actual probability as possible by simple processing. The soft decision device and method are used to output a soft decision value for each bit of each symbol used for decoding the each symbol as a value corresponding to the function value obtained by applying a predetermined function for each bit to the sampled value of the each symbol according to the demodulated signal such that the probability distribution of the sampled value in each symbol point is the Gauss distribution. The function for each bit is approximated to a curve expressing the probability that each bit is 1 or 0 for the sampled value of each symbol of the demodulated signal and defined by using a quadratic function.