New detector for 1,k codes equalized to class II partial response

A modified linear canceller is described which approached maximum-likelihood performance for a 1,k RLL code on a PR2 (class II partial response) channel. With white noise, this detector gains 1.8 dB over simple threshold detection. Performance is analyzed both theoretically and through bit-by-bit simulations for a variety of noise colorations and misequalization conditions. The technique is applicable wherever the channel is equalized to a low-pass characteristic as in instrumentation and video tape recording with Miller-squared code or optical recording with a 1,7 code and pulse-width modulation