Equalizer for the correction of digital signals

An equalizer for eliminating the effects of postcursor and precursor interference from a periodically sampled train of incoming digital signals, comprising:

• receiving means connected to a transmission path carrying said incoming signals;
• a first circuit branch connected to said receiving means, said first branch including first filter means for converting a given signal sample into a first linearly prefiltered signal with at least partial suppression of postcursor effects, first threshold means connected to said first filter means for deriving a first quantized pulse from said first prefiltered signal, second filter means connected to said first threshold means for generating a precursor-compensating signal from said first quantized pulse, first delay means connected to said first filter means for emitting a retarded signal corresponding to said first prefiltered signal, and first adding means connected to said first delay means and to said second filter means for algebraically combining said retarded signal with said precursor-compensating signal to produce a first purged signal;
• a second circuit branch connected in parallel with said first circuit branch to said receiving means, said second branch including third filter means for converting said given signal sample into a second linearly prefiltered signal with at least partial suppression of precursor effects, second threshold means in a feedback loop with an input end downstream of said third filter means for deriving a second quantized pulse from said second prefiltered signal, fourth filter means in said feedback loop connected to said second threshold means for generating a postcursor-compensating signal from said second quantized pulse, second adding means upstream of said input end connected to said third and fourth filter means for algebraically combining said second prefiltered signal with said postcursor-compensating signal to produce a corrected feedback signal, and second delay means connected to said second adding means downstream of said input end for emitting a second purged signal temporally correlated with said first purged signal;
• summing means connected to said first and second branches for algebraically combining said first and second purged signals into a resulting signal;
• and
• decision means connected to said summing means for converting said resulting signal into a quantized output pulse.