On Unique Localization of Uncorrelated Constant-Modulus Sources Using Sparse Linear Arrays

In direction-of-arrival (DOA) estimation, both stochastic and deterministic priors of source signals have been used to localize more sources than sensors. The stochastic prior refers to uncorrelateness of sources, while the deterministic one includes the constant modulus (CM) property of sources. Existing studies typically exploit one of the two priors. In this paper, we consider the combination of the two priors and present a necessary condition for unique localization of uncorrelated CM sources using a sparse linear array. Our result indicates limited benefits of exploiting both uncorrelated and CM priors in further improving the number of locatable sources.