EM‐MODE in high‐resolution DOA estimation for nonuniform array

Recently, the superresolution method has attracted significant attention as a high-resolution method of estimation of the electromagnetic wave propagation environment for mobile communications as well as various kinds of wireless communications. With regard to the array shape used in the estimation problem of direction of arrival, various array configurations in addition to equally spaced arrays have been studied. Weiss and colleagues have proposed a method of realizing a virtual equally spaced array by applying the EM method and the IQML method to nonuniform arrays. In this paper, the EM-MODE method based on this algorithm is proposed for estimation of the direction of arrival of the coherent wave by a nonuniform array and for improved processing. It is shown that improvement of the estimation success rate is possible by applying the improved processing in cases where estimation by the conventional EM-MODE method is difficult. The errors in estimation of the direction of arrival when this method is applied are studied. It is shown that much better characteristics can be obtained than when real elements are equally spaced. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(8): 47–56, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1117