DOA estimation of coherent signals on uniform circular array in the presence of mutual coupling

In this paper, a DOA (direction of arrival) estimation method of coherent signals based on uniform circular arrays, in the presence of sensor mutual coupling, is proposed. Firstly, the array considering mutual coupling is transformed into a virtual array of geometric proportion through preprocessing. Then a new covariance matrix is reconstructed with the eigenvector corresponding to the largest eigenvalue, which consists of all signals' information. In addition, the new signal covariance matrix is diagonal, which means a complete de-correlation. Finally, DOA can be estimated in conjunction with MUSIC algorithm based on the new covariance matrix. Compared with conventional methods, it has higher angular resolution and lower SNR (signal to noise ratio) threshold. Besides, this method also works well in the presence of mutual coupling between sensors.