US 7,599,441 B2
Low complexity soft-input Viterbi decoding for digital communication systems
Jun Ma, Irvine, Calif. (US); and Nabil Yousef, Foothill Ranch, Calif. (US)
Assigned to Newport Media, Inc., Lake Forest, Calif. (US)
Filed on Jun. 20, 2006, as Appl. No. 11/471,187.
Prior Publication US 2007/0291864 A1, Dec. 20, 2007
Int. Cl. H04L 5/12 (2006.01); H04L 23/02 (2006.01); H04L 27/06 (2006.01)
U.S. Cl. 375—262  [375/261; 375/341] 17 Claims
OG exemplary drawing
 
1. 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

OG Complex Work Unit Drawing
wherein cl represents transmitted code of said binary bit stream, wherein m0 represents a minimum Euclidean distance from a received soft decision symbol to hard decision symbols in a subset of constellation points with an ith bit equal to zero, and wherein m1 represents a minimum Euclidean distance from said received soft decision symbol to said hard decision symbols in said subset of constellation points with said ith bit equal to one; and
a Viterbi decoder operatively connected to said de-interleaver.