Patent ID: 7599441

Claim:
A communication system comprising: a convolutional encoder; an interleaver operatively connected to said convolutional encoder; a quadrature amplitude modulation (QAM) mapper operatively connected to said interleaver; a channel component operatively connected to said QAM mapper; a QAM demapper operatively connected to said channel component; a de-interleaver operatively connected to said QAM demapper, wherein said de-interleaver is adapted to decode a soft decision metric computation comprising a log-likelihood ratio (LLR) soft decision metric of a binary bit stream of a signal, and wherein said LLR corresponding to said binary bit stream of a signal equals 1 4 ⁢ ( m 0 ⁡ ( c l ) - m 1 ⁡ ( c l ) ) , wherein c l represents transmitted code of said binary bit stream, wherein m 0 represents a minimum Euclidean distance from a received soft decision symbol to hard decision symbols in a subset of constellation points with an i th bit equal to zero, and wherein m 1 represents a minimum Euclidean distance from said received soft decision symbol to said hard decision symbols in said subset of constellation points with said i th bit equal to one; and a Viterbi decoder operatively connected to said de-interleaver.