Efficient real-valued DOA estimation based on the trigonometry multiple angles transformation in monostatic MIMO radar

A novel real-valued polynomial rooting-based (RV-root-MUSIC) algorithm is proposed for efficient DOA estimation in monostatic MIMO radar. RV-root-MUSIC exploits the trigonometry multiple angles formula and variable substitution technique without transformation approximations to convert the original complex steering vector into a real one with respect to the cosine and sine functions. As such, RV-root-MUSIC implements the real-valued computation for both tasks of EVD and the polynomial rooting since the coefficients of polynomial are real. Numerical simulations are applied to demonstrate that with significantly reduced complexity, such trigonometry transformation is able to provide the similar performances as compared to the conventional root-MUSIC and U-root-MUSIC.