Securing Wireless Localization: The Role of Power Allocation in Location Privacy Protection

With high-precision location information becoming increasingly essential, the prevail of wireless localization networks has raised concerns about the growing risk of location privacy disclosure. Existing privacy-preserving strategies, such as encryption and noise addition, often suffer from drawbacks like high computational complexity and accuracy degradation. This paper explores the potential for enhancing location privacy protection through power allocation during the transmission of measurements. We begin by defining a location secrecy metric, which is dependent on transmitted power, to quantify the risk of an agent’s location being exposed, considering a general measurement model of eavesdroppers in wireless localization systems. Using this metric as a privacy constraint, we formulate an optimization problem for power allocation that aims to minimize the agent’s localization error while ensuring the required level of location privacy protection in both non-cooperative and cooperative localization scenarios. The resulting problems are challenging due to their nonlinear objective and constraint functions. To address this, we reformulate the problem into a tractable form using fractional programming and a series of problem transformations, converting it into a semidefinite programming (SDP) form. Numerical results validate the efficacy of the proposed strategy in protecting privacy and demonstrate its superiority over existing strategies in balancing localization accuracy. Additionally, the analysis provides valuable insights into the trade-off between localization accuracy and privacy protection.