Importance

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Abstract

An echo canceller according to the present invention includes means for storing an impulse response in a memory, the impulse response being indicative of the characteristics of a transmission line. It also includes a detector for detecting ranges of samples within the impulse response having relatively large distribution of echo energy, these ranges of samples of relatively large distribution of echo energy being indicative of echoes on the transmission line. An echo canceller includes a digital filter having a plurality of weighted taps, each of the weighted taps having an associated tap weight value. A tap allocation circuit establishes the tap weight values in response to said detecting means so that only taps within the regions of relatively large distributions of echo energy are turned on. The ranges of echo energy are detected coarsely by detecting ranges of samples having relatively high estimated average echo power. The echo is more finely located by computing the terms analogous to the mechanical computation of the center of gravity type calculation referred to as a `center of echo` and radius of gyration type calculation referred to as `radius of echo` of the echo energy within the coarsely located ranges of samples.

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First Claim