Coarse estimation of the incident angle for VLP with an aperture-based receiver

Recently, an estimation algorithm for the angle-of- arrival (AoA) for visible light positioning (VLP) was investigated [1]. In this paper, the authors considered an aperture-based receiver, and estimated for each light beacon the incident angle and polar angle between the beacon and the receiver using an iterative maximum likelihood (ML) based algorithm. For the iterative ML algorithm to converge, an accurate initial estimate was required. To obtain this initial estimate, a coarse ad hoc estimation algorithm for the incident angle was proposed. However, the proposed estimator for the incident angle was not able to deliver sufficiently accurate estimates for a wide range of incident angles, resulting in slow convergence of the iterative algorithm and large positioning errors. In this paper, we propose three novel estimators for the incident angle that are not only more accurate than the coarse estimator proposed in [1], but also have a wider estimation range.