Experimental verification of Best Linear Approximation of a wiener system for binary excitations

The Best Linear Approximation (BLA) is a linearisation of the transfer characteristics of a nonlinear system in a least squares sense. The BLA is known to depend on the statistical properties of the input signal used to identify it. The theory for Gaussian input sequences has been known for several years, but the corresponding theory for binary input sequences has only recently been developed. In this paper, experiments on a physical electronic Wiener system, aimed at verification of predictions made for the differences between BLA's estimated using Gaussian sequences and those estimated using binary sequences, are described. The results were found to be a good match with the theory but difficulties encountered during the experiment highlight a need for further work in extending the discrete-time theory to the continuous-time domain.