A lower bound on the cutoff rate for Gaussian channels with peak-limited inputs

A lower bound on the cutoff rate R_O of a dispersive Gaussian channel with peak- rather than average-power-limited input is evaluated and compared to the lower bound on capacity under the same input constraints. It is assumed that the input symbols are independent and uniformly distributed. Both bounds exhibit the same behavior as a function of an appropriately defined signal-to-noise ratio (SNR), with a discrepancy of 1.68 dB to the disadvantage of R_O, at high SNRs. The lower bound on R_O is evaluated for peak- and slope-limited signals that model magnetic recording systems and is compared to the lower bound on capacity