Recovery of Signals Distorted by Sensor Nonlinearity

Abstract

Considered in this paper is a framework for addressing sensor issues that are related to nonlinearity. When a signal is picked up by a nonlinear sensor, it is often the case that the high amplitude part of the signal is distorted by nonlinearity and the low amplitude part is indistinguishable from noise. The distorted output or sensed signal may no longer represent the original input signal due to the presence of high and low frequency foreign spikes in its frequency spectrum. This situation poses a challenging problem: Would it be possible to uniquely extract the original information from the distorted output? A treatment of this problem is given and it is shown that unique signal recovery is possible when the nonlinear characteristics of the sensor satisfy certain requirements. Based on the analysis, an algorithm is developed to recover finite length signals and its validity and efficiency are demonstrated by simulation results. When the sensor model is not available, it is shown how a model identification scheme may be incorporated into the developed scheme. Experiments performed on a physical sensor support the proposed recovery scheme.