Direct-Unitary MUSIC: A Real-Valued Method for Co-Array-Based Direction-of-Arrival Estimation
Guangming Song, Xinghao Qu, Zhigang Shang, Gang Qiao, Tianshui Li · 2024
Spatial smoothing (SS) has become a common technique targeted at direction-of-arrival estimation based on sparse linear arrays, which rearranges the corresponding co-array model to favor subspace methods. This paper provides the insight that the resulting matrix will possess the centro-Hermitian structure. To fully leverage this underlying property, we directly apply unitary transformation to the structured matrix and propose a real-valued subspace algorithm called direct-unitary MUSIC (DU-MUSIC). The crucial advantage of DU-MUSIC is that the steps of eigendecomposition and spectrum search can be performed in the real domain. Furthermore, such computational convenience will not compromise the algorithm performance. Analytical derivations and simulations verify the equivalence of DU-MUSIC and the classical SS-based MUSIC in terms of spatial spectrum performance.