A Study of Random Channel Errors for an ADM System

This paper constitutes a mathematical analysis of the effects of random channel errors when the transmitted signal is in adaptive delta modulation (ADM) format. This study not only permits us to model the behavior of an ADM signal, with respect to errors, but also provides a method for controlling excessive signal distortion, particularly for high bit error rates. Our analysis shows that the decoded error signal exhibits both a dc and an ac component. The dc error is controlled with a leaky accumulator and an appropriate output filter. The ac error is shown to be proportional to the original signal and we are able to control its amplitude by artificial error injection. This yields an effective way of improving performance in a noisy environment. We present computer simulation results to verify our analysis and error control with a variety of test signals.