Method and apparatus for equalization and tracking of coded digital communications signals

摘要

A symbol detector provides a delay-less estimate of a transmitted symbol. The symbol detector includes a symbol input for receiving a sequence of input symbols, a plurality of accumulators (ACC) for storing trellis state costs, a plurality of adders (202) for summing the square of distances between an input symbol and a constellation symbol for a trellis branch with the trellis state costs, and a plurality of comparators (203) connected to the adders for determining minimum costs and providing those costs to the accumulators. A memory (201) is connected to an associated comparator for storing the minimum cost determined the associated comparator. A minimization unit (204) outputs an index value of comparators with the lowest value, and a branch table unit (205) outputs a delay-less estimate of a transmitted symbol based on the index of the trellis branch with lowest cost that enters the trellis state with lowest cost and an input symbol.