Exploiting Two-Dimensional Symmetry And Unimodality For Model-Free Source Localization In Harsh Environment

Knowing the location of a transceiver may enable advanced radio resource management strategies in sensing and communication networks. However, there are many scenarios where users operate in a non-cooperative mode with no localization-dedicated signaling with the network. As a result, conventional timing-based or propagation-model-based localization methods cannot be applied. This paper studies a model-free source localization problem where sensors only measure received signal strengths from a wireless signal source. The only assumption made is that the received signal strength decays homogeneously in all directions from the source. A measure of two-dimensional symmetry is developed via monotonic curve fitting to exploit the hidden symmetry and unimodality of the propagation. Based on this, a non-parametric source localization algorithm is derived. It is demonstrated that the proposed algorithm significantly outperforms weighted centroid localization algorithms, and, in the low noise regime, a more than 50% of error reduction is observed.