Volume 2, Issue 11, December 2012

Performance Enhancement of High Resolution Multiple Widebandand Nonstationary Source Localization with Unknown Number of Sources [Download Paper]

Sandeep Santosh and O.P. Sahu

Abstract- In this paper, Performance Evaluation of high-resolution multiple wideband and nonstationary source localization using a sensor array is presented. The sensor array’s received signals are first converted into time- frequency domain via short-time Fourier transform (STFT)and it is found that a set of power spectrum matrices at different time instants havethe joint diagonalization structure in each frequency bin. Using such a joint diagonalization structure, a novel cost function is designed and a new spatial spectrum for direction of arrival(DOA) estimation is obtained.The algorithm in this paper obtains the DOA estimates via one –dimensional (1-D) search instead of multidimensional search.It’s computational complexity is much lower than the ML method.For this algorithm ,it is not necessary to determine the number of sources in advance unlike the subspace based high- resolution DOA estimation techniques .The algorithm used in this paper is robust to the effects of reverberation caused by multipath reflections. It is suitable for multiple acoustic source localization in a reverberant room. 

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Performance Enhancement of Robust Expectation-Maximization Direction of Arrival Estimation Algorithm for Wideband source Signals [Download Paper]

Sandeep Santosh and O.P. Sahu

Abstract-In this paper, we tackle DOA estimation problem based on realistic assumption that the sources are corrupted by spatially nonwhite noise. We explore the limitations of two popular DOA methods to solve this problem – the stepwise concentrated maximum likelihood (SC-ML) and approximately concentrated maximum likelihood (AC- ML) algorithms and design a novel expectation maximization (EM) algorithm. Through Monte Carlo simulations , it is demonstrated that our proposed EM algorithm outperforms the SC-ML and AC-ML methods in terms of DOA estimation accuracy and computational complexity.