Broadband correlation detection method based on normal mode extraction

Due to environment disturbance, interference between the normal modes, and the ambient noise, the spatial correlation between received signals is attenuated. In this paper, we consider the problem of detection performance degradation caused by spatial correlation attenuation, and a broadband correlation detection method based on the normal mode extraction is proposed accordingly. The method extracts the normal modes from the received signals by warping transformation to increase the spatial correlation and uses the extracted normal modes as the inputs to detectors to determine whether the signal exists or only noise is present. Theoretical analysis and computer simulations are carried out. Results show that both the signal spatial correlation and signal-to-noise ratio are increased by extracting the normal modes, and that a better performance is obtained by the proposed detection method compared to the conventional one.