Toeplitz rectification based DOA estimation under the coexistence of mutual coupling and nonuniform noise

Abstract

It is studied that both the array mutual coupling (MC) and nonuniform noise could degrade direction-of-arrival (DOA) estimators’ performance substantially, and thus it is of necessity to eliminate them before performing DOA estimation. In this paper, two Toeplitz rectification (TR) based methods for DOA estimation under the coexistence of MC and nonuniform noise are proposed. The first method jointly employs the middle subarray scheme and TR to immunize the effects of MC and nonuniform noise, and further applies the estimation of signal parameters via rotational invariance techniques (ESPRIT) to obtain closed-form DOA estimates. This method can yield a good and low-complexity result. The second method first exploits the least squares (LS) criterion to eliminate the nonuniform noise, and then enhances the major part of sample covariance matrix (SCM) via the TR. With this enhanced SCM and subsequent two-stage spectral searches, an improved DOA estimation is provided. Simulation results validate the effectiveness of the proposed two methods.