Ambient Interferences Suppressing for In-Situ Radiated Emissions Measurement Based on Array Signal Processing and Adaptive Noise Cancellation

In this article, a method combining array signal processing and adaptive noise cancellation is proposed to suppress the ambient interferences of in-situ measurement. First, the directions of arrival and classes of all signals are obtained by performing blind source separation and sparse reconstruction on the received signals. Then, the received signals are reused to form two different data channels. In both channels, the interferences that are coherent with the radiated signals of the equipment under test and have larger amplitudes are eliminated based on null trap forming, whereas the coherent interferences with smaller amplitudes are ignored after being attenuated. Besides, the other interferences are suppressed by the adaptive noise cancellation based on their correlation in the two channels. For transient signals, overlapping window technique is used to avoid the losses of the spectrums. Each frame of the signals is cyclically extended to provide sufficient points for adaptive noise cancellation. The proposed method achieves the suppression of multisource ambient interferences with fewer array elements. Simulation and experiment results are given to verify the effectiveness and accuracy of the proposed method.