Study of a Novel ADM Algorithm with Pre-processing for Performance Improvement

In this paper, a novel technique of a step-size adaptation algorithm for improving the signal-to-noise ratio (SNR) of Adaptive Delta Modulators (ADM) with one-bit quantization is presented. The two existing step-size algorithms--SONG and modified ABATE are discussed and also their performance comparison is made. For further improvement in the SNR with the proposed ADM includes an ADM with pre-processed signals which is also described. Large variations in the input signal require larger step sizes. If step size is not increased, it leads to slope-overload error. These large variations in the input signal are removed/smoothened by a suitable pre-processing method, one of which is using an integrator that can smoothen the rapid changes. From simulations it is confirmed that the new step-size algorithm for the ADM with pre-processing (proposed ADM) leads to an improvement in the SNR compared to the conventional ADM.