Adaptive continuous-time equalization followed by FDTS/DF sequence detection

Employing an adaptive continuous-time forward equalizer with a Fixed Delay Tree Search with Decision Feedback (FDTS/DF) detector provides several advantages to a magnetic recording system. Although an adaptive continuous-time filter of modest complexity cannot achieve the degree of pulse shape control provided by a long FIR filter, its power consumption may be dramatically lower. An FDTS/DP detector can be easily adapted to widely varying equalized pulses. By combining the two, we can achieve channel performance comparable to that of a system including an FDTS/DF detector and a long FIR equalizer-but with a power dissipation that is potentially much less than conventional sequence detection channels. Simulation results are presented that compare this new approach with a finite length FIR equalizer followed by an FDTS/DP detector. We present and compare several architectures for the adaptive continuous-time equalizer that offer improved convergence when using the least-mean-squares (LMS) adaptation algorithm.<>