Eye Opening Degradation due to Sideband Suppression in Direct Detection Systems for Different Signaling Formats

Abstract

The intensity distortion resulting from sideband suppression in direct detection systems is investigated analytically and through numerical simulation for unipolar binary and alternate mark inversion formats. A method to calculate the sequence leading to the highest eye opening penalty is proposed, based on the characterization of the distortion originated by the Hilbert transform of an isolated pulse and constructive/destructive addition of the distortions of pulses in different time slots. The application of the proposed method to a practical transmitter is assessed, and accurate results are shown for signals without complete sideband suppression.