Speed Estimation Using Relative Radio Frequency Signature Matching

One of the largest obstacles to effective navigation and positioning using pedestrian dead reckoning is the lack of accurate speed estimation algorithms. Existing methods are either complex or provide results that are unsatisfactory at low velocities associated with pedestrians and other slow moving entities. In contrast, the algorithm proposed in this paper is simple to implement and is able to provide accurate results at low velocities. A one-dimensional and unidirectional two- antenna solution is described where the speed can be easily estimated from a knowledge of the fixed inter-antenna distance and the time it takes for the trailing antenna to experience the same channel conditions (radio frequency (RF) signature) as the leading antenna. Computer simulations of the new adaptive algorithm show that with estimation errors of less than 1.2% around average pedestrian speeds the approach is indeed effective and accurate.