APPARATUS FOR GENERATING DOWN LINK SIGNAL, AND METHOD AND APPARATUS FOR DETERMINING THE LOG-LIKELIHOOD RATIO IN CELLULAR SYSTEM

摘要

An apparatus for generating a down link signal, and a method and an apparatus for restoring data in a cellular system are provided to improve calculation efficiency of LLR(Log-Likelihood Ratio) for a soft decision by calculating interference fading and noise. A method for restoring data in a cellular system includes the steps of: performing equalization for compensating delivering time delay deviation and reduction for each frequency included in a received signal(S110); detecting interference element caused by fading inside a cell, and channel coefficients including fading element generated by neighboring cells(S120); detecting a dispersion of an AWGN(Additive White Gaussian Noise) element included in the received signal(S130); calculating the dispersion of entire noise element which the fading element and AWGN is considered(S140); calculating an LLR for a corresponding received signals(S150); and deciding the received signal by performing a soft decision by using the LLR.