METHOD FOR DETECTING A DISCRETE SYMBOL SEQUENCE FROM AN OBSERVATION SIGNAL, AND VITERBI PROCESSOR IMPLEMENTING SUCH METHOD

摘要

The detection of symbols of a sequence on the basis of anobservation signal (R) is performed in accordance with a soft output Viterbialgorithm using a trellis. In order to assign a likelihood (.LAMBDA.m) to adiscreteestimation (~m) of a symbol, the difference between the metrics of the optimalpath determined in accordance with the Viterbi algorithm and the metrics of acompetitor path which is optimal among all the paths leading to a differentdecision for the symbol in question is calculated, the metrics beingconsideredon the whole length of the trellis.