Search-free decentralized direction-of-arrival estimation using common roots for non-coherent partly calibrated arrays

We consider decentralized direction-of-arrival (DoA) estimation for large partly calibrated arrays composed of multiple fully calibrated uniform linear subarrays. Due to the difficulty of maintaining coherence between signals received in widely separated subarrays, the practical case of non-coherent subar-rays is investigated. Our novel approach for decentralized and non-coherent DoA estimation is based on finding the common roots (CRs) of multiple univariate polynomials corresponding to individual subarrays. We propose two algorithms using generalized Sylvester matrix to find the CRs and to estimate the DoAs. The proposed algorithms substantially reduce communication and computation costs compared to traditional centralized DoA estimation methods. Moreover, simulation results demonstrate that our algorithms outperform existing decentralized methods and can deal with possible DoA estimation ambiguities caused by subarray geometries.