On Temporal Smoothing for Two-Dimensional Direction-of-Arrival Estimation of Coherent Signals in Multiplicative/Additive Noises Environment

In this paper, temporal smoothing technology is extended for solving two-dimensional (2-D) direction-of-arrival (DOA) estimation of coherent signals problem in multiplicative/additive noises environment. To detect the signals of interest (SOIs) from complicated noises and interferences, a 2-D DOA estimation algorithm is firstly proposed exploiting third-order cyclic moment of cyclostationary signals. Due to the more rapid changes of multipath reflection coefficients than their DOAs in real wireless scenarios, temporal smoothing to resolve multiple directions of coherent signals is considered, which is helpful in solving the angle ambiguity problem in 2-D estimation case using a planar array. Compared with spatial smoothing based 2-D method, in which multiple sub-planar array structure need to be grouped, the proposed method has less complexity and further array aperture extension. Also, it can detect SOIs, suppress multiplicative/additive stationary noises and remove interfering signal with different cyclic frequency