Application of Ray-Tracing for the Mobile Localization using the Direction of Arrival and the Received Signal Strength

The problem of 3D-radiolocalization in indoor environments with Line Of Sight (LOS) and Non Line Of Sight (NLOS) conditions has been investigated in recent years. Many people in academia and industry are currently involved in the research and development of these kind of approaches. The aim of this communication is to find a simple method that decreases the errors due to the absence of LOS and to the multipath reflections. This work presents a new indoor localization method based on the fingerprinting technique. The proposed method uses a Ray-Tracing model that can be obtained by using FASPRI tool [1]. FASPRI is a Ray-Tracing code based on Geometric Optics and the Uniform Theory of Diffraction. An advantage of using the Ray-Tracing technique is that information can be obtained about the multipath effects. All this information is stored in a dataset during the first stage of the fingerprinting method. Direction of Arrival (DOA) of the rays and Received Signal Strength (RSS) are used in the fingerprinting technique to implement a hybrid system. The advantages of the proposed approach are that it is very useful for practical applications, neither a new hardware nor an extra sensor network installation is required and it increases the accuracy with respect to similar approaches, especially in mixed LOS/NLOS conditions.