In-Field Calibration of a Multi-Mode Antenna for DoA Estimation

Abstract

State-of-the-art radio localization methods often rely on estimating the signal direction-of-arrival (DoA) or direction-of-departure (DoD). This requires careful calibration of the antenna, including surrounding structure, in a measurement chamber. Alternatively, auto-calibration algorithms can be used for certain types of phased arrays. However, they cannot correct all model errors and cannot be applied to other types of multiport antennas like multi-mode antennas (MMAs) or collocated antennas. In this paper, we present a maximum a posteriori (MAP) in-field calibration algorithm based on wavefield modeling and manifold separation for arbitrary multiport antennas. The algorithm is evaluated using measurements of a four-port MMA mounted on a rover. A significant performance gain for DoA estimation using in-field calibration is achieved compared to calibration in a chamber.