Evaluation of Digital Signal Using Eye Diagram

Abstract

Digital system with theoretically infinite bandwidth is distortion less over all frequencies. However, in practical terms, every digital transmission system has a finite bandwidth with a certain varying amount of frequency response distortion. Here the pulses tend to spread out and overlap causing what is called Inter Symbol interference. This impairment can be minimized by pulse shaping, equalization and other methods. The degradation is assessed by means of an eye diagram. The diagram used to illustrate how the received signal level can be less than the transmitted signal level due to the influence of the transmission impairments.