a method for reducing interblock interference in an impulse response signal transmitted by a communications channel such as a digital subscriber loop channel . the method includes computing a time of reference based on a windowing function that assumes that the main lobe segment of the impulse response signal does not contribute ibi power and that the tail segments of the impulse signal , which fall outside of the main lobe segment of the impulse signal , contribute a non - uniform amount of ibi power . the method reduces ibi in the impulse response signal beyond that of conventional ibi reducing methods .