A unitary transformation method for DOA estimation with uniform circular array

Subspace based direction-of-arrival (DOA) estimation algorithms in the uniform circular array (UCA) scenario involve complex computations, which results in high hardware implementation complexity. To solve this problem, a unitary transformation method in element space is proposed. Using this method, which exploits the centrosymmetry of UCA, real-valued covariance matrix and steering vectors can be obtained, thus the hardware implementation complexity is significantly reduced; furthermore, the MUSIC algorithm based on this unitary transformation method performs better than both conventional MUSIC and the unitary MUSIC in phase mode space of the UCA.