Eye Diagram Degradation on Teletext Signal Caused by Nonlinear Distortion

Abstract

It is difficult to calculate the nonlinear distortion on a Teletext signal, because the superpose-method, based on single pulse responses, cannot be used to calculate nonlinear distortions appearing in an eye diagram. However, the nonlinearity of transmitters and receivers cannot be ignored when it is necessary furnish high quality Teletext service.
The authors, using a computer-simulation method, make some calculations for eye height evaluation degraded by both amplitude and phase nonlinearity, and show the results in typical cases of well-known nonlinear curves and quadrature distortion. Those results may be useful for considering the nonlinearity influences in transmitters, translators and receivers, and also may be useful for determining nonlinear compensator design.