On mutual coupling for ULAs: Estimating AoAs in the presence of more coupling parameters

The problem of Angle-of-Arrival estimation of multiple sources in the presence of mutual coupling is addressed. The presence of unknown mutual coupling between antenna array elements is known to degrade the performance of direction-finding algorithms. We first present a result explaining why some traditional methods, that estimate Angles-of-Arrival (AoAs) of multiple sources in the presence of mutual coupling, suffer from an identifiability issue, when the number of coupling parameters exceeds a certain level. Then, we present a first method that estimates AoAs of sources when more coupling parameters are present, namely when the number of coupling parameters exceeds that certain level. Finally, we propose a refinement of the proposed algorithm, which could further enhance the AoA estimates. Simulation results have demonstrated the potential of the proposed method and its refined version, for different scenarios, as it enjoys better performance than existing methods. A better description of the paper could be found in the Conclusions section.