DOA estimation of unequal power signals in non-ideal electromagnetic environment
Jinsong Wang, Jun Wang, Yujie Du · 2022
Invariant property of noise subspace algorithm based on manifold separation technique (IPNS-MST) is proposed to estimate the direction of arrival (DOA) of unequal power signals in the non-ideal electromagnetic environment. Firstly, the manifold separation technique is used to separate the steering vector of the antenna array, and the amplitude and phase error, position error, and mutual coupling error are taken into account so that the algorithm can be applied to arbitrary array structures. According to the invariant property of noise subspace theory, when the incident signal power changes, the noise subspace remains unchanged. Compared with the general estimation algorithm, the proposed algorithm characterizes the energy of signal space and noise space with eigenvalues. IPNS-MST algorithm reduces the requirements of distinguishable strong and weak signals ratio (SWR) and the signal-to-noise ratio (SNR) of weak signals. Moreover, numerical experiment results verify the effectiveness of the proposed algorithm.