Maximum likelihood near field localisation using concentric circular ring array

This paper proposes a technique to estimate signal parameters for the localization of near-field sources by using concentric circular ring antenna array. The concentric ring array has the property of frequency invariance over certain band of frequencies that can help in localizing wideband sources from received wideband signal. Maximum likelihood (ML) method is applied for parameter estimation of near-field radiating sources. Unlike subspace based methods, ML technique does not require preprocessing for wideband source localization. Since ML cannot identify the number of sources automatically, the concept of alternating projection method is applied with the maximum likelihood method to identify the number of sources present.