Method of Identifying Volterra Frequency-Domain Kernels Based on Stimulus of Multi-tone Signal

In order to solve the problem of difficultly identifying Volterra frequency-domain kernels, the output properties of Volterra frequency-domain kernels stimulated by multi-tone signal were investigated, and a novel non-parametric method to identify Volterra frequency-domain kernels was proposed based on multi-tone stimulus. With this method, a multi-tone signal with a proper frequency basis is selected as the test stimulus signal to make each kernel put out unique frequency components, further the output of each kernel is separated by the Vandermode method. The formula to identify Volterra frequency-domain kernels was derived, and theoretical and simulation analyses were carried out. The results indicate that any order Volterra frequency-domain kernel can be precisely identified by the proposed method, and the order of magnitude of the absolute error is 10-4 V. The proposed method overcomes the defects of the conventional methods, i.e., they are unable to correctly identify Volterra frequency-domain kernels and the identification results are limited to the first three orders, and it has a high precision and is easy to operate.