Channel equalization via channel identification for rapidly fading HF channels

The emphasis is on the implementation of a fractionally tap-spaced DF equalizer (DFE). It is found that, in terms of tracking the CEQCID is far superior to the least squares (LS) based direct equalization methods widely assumed to be the best for tracking of the rapidly varying channels. In terms of computational complexity and robustness to roundoff error accumulation, also, the CEQCID based data receivers are superior to their LS counterparts. The fractionally tap-spaced DFE is also compared with the matched filter followed by the symbol interval DFE structure that has been suggested by Fechtel and Meyr (1991) and used in a CEQCID based data receiver. It is shown that the former is a better choice for the multipath HF channels.