A Beamspace DOA Estimation Algorithm for Non-circular Signals

Beamspace Root-MUSIC (BM-RTMUSIC) algorithm cannot resolve coherent sources, and the use of spatial smoothing pre-process leads to array aperture loss and reduction in detectable source numbers, a new beamspace conjugate Root-MUSIC (BMC-RTMUSIC) algorithm is proposed to estimate the Direction-Of-Arrival (DOA) for non-circular signals. The proposed method employs the properties of noncircular signal to construct a conjugate symmetric Toeplitz matrix from received data vectors, and forms the pseudo covariance matrix. It then estimates the source DOAs through the techniques similar to BM-RTMUSIC method. The proposed method does not require forward/backward spatial smoothing for the covariance matrix, hence decreasing the computational load and time. Simulation results show that the proposed method can resolve coherent and noncoherent sources using few snapshots and its performance is better than the BM-RTMUSIC method, especially in low SNR.