Observability Analysis of Multipath Assisted Target Tracking with Unknown Reflection Surface

This paper analyzes the problem of incorporating multipath measurements from an unknown reflection surface for improving the tracking result of a single target. The characteristic of the reflection surface, such as location and the slope, should be known in order to use the multipath measurements for track initialization or filtering. However, in a real-world problem, the reflection surface is mostly unknown or partial information about the reflection surface is known. If the problem of estimating the unknown parameters of the reflection surface is observable with the direct and multipath measurements, then the multipath measurements from the unknown reflection surface could be used to improve tracking performance. In this paper, a tracking framework is proposed to track a single target with an unknown reflection surface, and the Fisher Information Matrix (FIM) is derived for the considered problem to examine the observability. In addition, simulation results showing the performance of multipath-assisted tracking and the performance bounds are also provided.