A simulation study of adaptive reception schemes for high-density digital magnetic storage

At high information densities, digital magnetic recording systems may be seriously hampered by channel imperfections such as intersymbol interference, noise, fading, nonlinearities, crosstalk, and overwrite noise. For such compound disturbance constellations, theoretical analysis of receiver performances becomes difficult. As an alternative, the digitized output signal of an experimental high-density digital videotape recorder is used to compare various promising receiver types by simulation. Apart from adaptive versions of the linear and decision feedback equalizers, adaptive variants of the Viterbi detector are studied, including new ones with resistance to nonlinearities and channel fading. Improvements of up to about 5 dB in effective signal-to-noise ratio over nonadaptive linear equalization are found to be within reach under worst-case operating conditions