Channel memory truncation for maximum likelihood sequence estimation

Abstract

Calculating the coefficients of a linear equalizer (prefilter) so that the combined response of the equalizer and a given channel is forced to a limited length (memory), while the signal-to-noise ratio at the equalizer output is maximized, is addressed. The process involves simultaneous calculation of a desired response that the combination of the channel and equalizer should approximate and the equalizer coefficients. An iterative algorithm which is an extension of our previous work [4] is first developed. This is followed by derivation of a non-iterative lattice-based algorithm which uses the Levinson algorithm, in part, to achieve a very low computational complexity.