Multi-frequency distributed arrays for underdetermined direction-of-arrival estimation

Abstract

Distributed array can obtain a higher aperture than conventional uniform linear array, thus obtain high direction of arrival (DOA) estimation accuracy. However, the degree of freedom of the difference co-array of the distributed array has not been fully used. In this paper, the multi frequency is used to complete the missing elements of the co-array of the distributed array. The wideband sensor output is first transformed to the desired additional frequency via the discrete Fourier transform, and the holes of the covariance vector at the center frequency can be completed using the covariance matrix at the additional frequency. Then the high-resolution DOA estimation method SSMUSIC can be employed to the whole co-array. The proposed method has higher estimation accuracy than the single frequency distributed array in the underdetermined case. Simulation results show the effectiveness of the proposed method.