An Estimation of Nonlinear Distortions of Multifrequency Signals at the Transmitter Output in the Wireless Sensor Network

摘要

This article presents the structure of a multifrequency signal in OFDM technology with nonlinear distortions in the transmitter quantum of the sensor node. To quantify the degree of the signal distortion we propose an indicator in the form of a mutual correlation coefficient of the transmitter output signal and the reference signal. An analytical model of estimation of the signal nonlinear distortions was obtained, taking into account the dependence of this indicator on amplitude changes, frequency and phase parameters of the OFDM signal components. It has been shown that the choice of the corresponding phase-code structure of the OFDM signal can minimize the differences between the nonlinear distorted signal and the reference signal. The conclusion was made about the necessity of adaptive control of signal structures, which are formed in the transmitting nodes of the WSN, in case of reduction of the power supplies voltage.