Abstract:

Considering that the traditional direction of arrival (DOA) algorithms in the cumulant domain discard the repeated virtual array elements, a new algorithm for estimating the DOA of coherent signals based on focusing preprocessing in the fourthorder cumulant domain is proposed. First, the reasons for the failure of decorrelation are analyzed from the lost of shift-invariant characteristics in the virtual arrays. Then, the principle of decorrelation and DOA estimation of coherent sources is deduced by using the focusing technology. Finally, algorithms of direct focusing, forward/backward focusing and quadratic forward/backward focusing in the cumulant domain are proposed and their performances are analyzed. The analysis shows that, the new algorithms not only avoid the reduction of the array effective aperture but also make full use of the data of the virtual array, they have higher resolution of DOA estimation than similar algorithms. Theoretical analysis and simulation results demonstrate the merits of the new algorithm.