Optimal placement of reference nodes for wireless indoor positioning systems

Accuracy of location determination is one of the keys to success of any indoor positioning system. This performance metric is influenced by how reference nodes (RNs) are installed. However, most of existing research studies ignored the problem of optimal reference node placement and efficient system design for indoor positioning systems. In this paper, we propose an optimization technique that can be used to optimize the placements of reference nodes and improve the location determination performance. A mathematical formulation of reference node placement is developed as a Binary Integer Linear Programming (BILP) problem, which is an efficient approach generally applied in facility layout problems. The proposed formulation aims to minimize the number of reference nodes and search for their optimal locations in indoor positioning system. The performance study in this work is based on simulation model comparison of node placements found in the literature with the optimal node placement solutions obtained from our optimization. The results show that using optimal placement of reference nodes the indoor positioning systems can gain up to five meters of accuracy at 90% precision.