COMPUTATION OF SOFT BITS FOR A TURBO DECODER IN A COMMUNICATION RECEIVER

摘要

A device (20) for computing a threshold Sthi used in demodulating a quadrature amplitude modulated (QAM) signal to generate a plurality of soft bits per received symbol for input to a turbo decoder, the device including: means (30) for computing the mean amplitude A of the received symbols and multiplying the mean amplitude A by of the received symbols and multiplying the mean amplitude A by a constant Ci for a square QAM constellation with 4<m> points, such that Sthi = A x Ci where m is a positive integer and i is a positive integer from 1 to (√4<m-1>)-1.