Adaptive equalization and its effect on error models for digitally-modulated signals

In digital communications systems using adaptive equalization traditional modulation quality analysis may not faithfully represent or predict the system performance. Adding adaptive equalization to a measuring receiver can improve the fidelity of measurements and provide other benefits for troubleshooting as well. To take maximum advantage of the benefits of adaptive equalization it is important to use a more refined conceptual model for system elements such as transmitters or modulators, and for measuring receivers as well. Such models are discussed, along with their implications and benefits. Specific reference is made to more representative measurements, new measurement and data types, and their use in various parts of the product life cycle.