Improved decision directed adaptation and decision feedback equalizers are
provided in a block coded digital communication system. The performance
of a receiver is significantly improved by allowing the decision feedback
equalizer to perform time-tracking and residual frequency offset
compensation during the data portion of a frame. This is accomplished by
capitalizing on the inherent correlation among the chips of a code word
in a block coded digital communication system to identify certain
instances where more reliable symbol estimates can be derived from a
sliced chip without introduction the delay inherent in decoding. As the
more reliable symbol estimates are fed back into the chip slicer, the
total efficiency of the decision feedback equalizer is improved and the
more reliable symbol estimates can be used to replace older content in
the feedback filter to further improve the accuracy of the modified
slicer input and further decrease the effects of error propagation by the
decision feedback equalizer.