Optimizing the bit aspect ratio of a recording system using an information-theoretic criterion

A method is developed to determine the optimal bit aspect ratio of a recording system which maximizes the information density per unit area of the recording medium. The areal information density is computed as the achievable mutual information rate divided by the area of each binary symbol on the medium. A data-dependent autoregressive noise model is fitted to the recording channel and the achievable information rate of the recording channel is estimated by computing the achievable information rate of the channel model.