A Shadowing Loss Compensation Method for Hybrid RSS-Based Indoor Localization

Received signal strength (RSS) based localization schemes can be categorized as device-based localization (DBL) and device-free localization (DFL) in terms of the target to be located. DBL transforms RSS measurements of anchor-tag links to ranges and then obtains the target's position through trilateration. DFL infers an attenuation image from the target's body shadowing and regards the position with maximum attenuation as estimation. Existing hybrid method combining these two methods is able to improve the localization performance. However, the impact of the target's body shadowing loss on the anchor-tag links is not taken into consideration, worsening the localization accuracy of the DBL and hybrid method. In this paper, a new method is proposed to compensate the body shadowing loss by the exponential model on the basis of DFL result and the target's orientation. Experimental results validate that the compensation is beneficial and the proposed localization method is more reliable. Localization accuracy of the modified DBL is improved by 20% compared with the conventional DBL and the proposed hybrid localization method is 10% better than the conventional hybrid method.