Location Privacy Protection: A Power Allocation Approach

High-precision location information formulates the basis of many modern wireless location-based services (LBSs). However, location privacy becomes an important issue along with the advantages that LBS offer. In this paper, we first show that a novel eavesdropper is able to perform position estimation of the agent by purely overhearing the measurement signals between anchors and the agent, using a time difference of arrival way. Optimal power allocation-based approaches are presented to protect the location privacy against the eavesdropper. Then, high-accuracy approximation algorithms are also presented to solve the essential non-convex optimization problems. According to the numeric results, we can see that the presented power allocation strategies are able to prevent the eavesdropper from performing accurate position estimation of the agent. We can also see that there exists an optimal tradeoff between the system localization and privacy protection, which can be achieved by the presented frameworks.