LOS identification for high accuracy TOA-based ranging system in tunnel environments

The performance of localization systems is highly sensitive to the presence of the Line-Of-Sight (LOS) path. In indoor environments, where high accuracy is required, identifying the channel conditions can be a good solution to overcome the multi-path effects and reduce the ranging error. Most of existing algorithms are based on the statistical parameters of the channel response or the range error. However, these features are limited when a single antenna is utilized. In this work, we exploit the spatial diversity of a multi-antenna system for LOS identification. In the future 5G devices, one powerful technique used for spectrum awareness is the Compressed Sensing (CS). Therefore, its implementation in our ranging system will allow us to obtain fine time resolution whilst avoiding an additional complexity in the receiver architecture. The proposed approach has been evaluated in tunnel environment and has efficiently improved the ranging accuracy.