Direction estimation of uncorrelated and coherent narrowband signals with uniform linear array

In this paper, an effective direction-of-arrival (DOA) estimation method is proposed with a uniform linear array (ULA) when uncorrelated and coherent signals coexist. The direction-of-arrivals (DOAs) of uncorrelated signals and coherent signals are estimated in two steps. The DOAs of uncorrelated signals are estimated using conventional subspace method firstly, then the information of the uncorrelated signals can be eliminated by using matrix difference technique, and finally the coherent signals are decorrelated to be estimated. The theoretical analysis and simulation results show that the proposed method is effective.