A High Resolution Doa Estimating Method Without Estimating the Number of Sources

Abstract

Abstract-The performance of high resolution subspace-based algorithms are particularly sensitive to the prior information of the source number, the Signal-to-Noise Ratio (SNR) and the snapshot. Although the existing direction-of-arrival (DOA) estimation methods without estimating the source number could eliminate the awful impact brought by incorrect source number estimation, yet its performance would get deteriorated by small snapshots and low SNR. Methods which exploit noise and signal subspaces information simultaneously, such as SSMUSIC, could provide a high resolution performance in such nonideal circumstances. However, its performance would degrade severely when the prior information of the source number is incorrect. To provide a DOA estimation method without estimating the number of source, which has a high resolution performance in small sample and low SNR scenario, using all information spreads in eigenvalues and eigenvectors, this paper reconstructs a new spatial spectrum which is very similar to the SSMUSIC algorithm. In order to enhance the robustness of the new method, we provide an empirical method to modify the eigenvalues to prohibit the spreading of noise eigenvalues caused by snapshot deficient and low SNR. To verify the validity of the new method, comparisons with other algorithms are made in computer simulations and the measured data test.

Modified Doa Estimation Methods With Unknown Source Number Based on Projection Pretransformation

“…Through the simulations in [20], we know that the weights of signal subspace projection in SSMUSIC signal subspace function could be slightly changed. A new spectrum similar to SSMUSIC is given as…”

“…In [20], we infer approximate representations of MUSIC and SSMUSIC spectrums, in which the source number is unnecessary. In the ideal environment, we have:…”

“…In [22], it is used to improve the performance of adaptive beamforming. In this paper, on its basis, the methods proposed in [20] are further modified to get lower computational complexity and better performance.…”

“…In [20], we have developed a simple but high resolution DOA estimating method with unknown source number, suitable for the snapshot deficient and low SNR scenario. Through the equations provided in [20], the spectrums of MUSIC and SSMUSIC could be represented approximately, which eliminate estimating the source number in advance.…”

“…In [20], we have developed a simple but high resolution DOA estimating method with unknown source number, suitable for the snapshot deficient and low SNR scenario. Through the equations provided in [20], the spectrums of MUSIC and SSMUSIC could be represented approximately, which eliminate estimating the source number in advance. However, to avoid the awful impact brought by the spreading of noise eigenvalues in the snapshot deficient and low SNR scenario, a high computational complexity method is used, which needs to be simplified.…”