JOURNAL OF COMMUNICATIONS (JCM)

ISSN : 1796-2021

Volume : 4 Issue : 2 Date : March 2009

**Radio Frequency Signature Correlation Based Speed Estimation for Indoor Positioning**

Mostafa Afgani, Sinan Sinanović, Karim Khashaba, and Harald Haas

Page(s): 96-107

Full Text: PDF (585 KB)

**Abstract**

Dead reckoning represents a class of methods for relative position estimation based on a

previously determined absolute reference position. The estimate is formulated from a combination

of the known speed, time and heading information with the known reference position. One of the

main obstacles to effective positioning of pedestrians via dead reckoning is the lack of accurate

speed estimation algorithms. Existing methods are either complex or provide results that are

unsatisfactory at the low velocities associated with pedestrians. In contrast, the two algorithms

proposed in this paper are relatively simple to implement and provide accurate results at low

velocities. In the first algorithm, 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 sense the same channel conditions (radio

frequency (RF) signature) previously observed at the leading antenna. Computer simulations show

that, with typical estimation errors of less than 2.67% around average pedestrian speeds, the

approach is indeed effective and accurate. A by-product of the algorithm is an environment specific

spatial correlation function which is used in the second algorithm to provide even better estimates.

With the improvements offered by the latter algorithm, relative errors of merely around 0.15% on

average are achievable. This improvement in performance over the first algorithm comes at the cost

of slightly higher computational complexity. When subsequently used for user displacement

estimation, a relatively small error of 24.5cm is observed after a duration of 60s.

**Index Terms**

speed estimation, pedestrian dead reckoning, spatial correlation, radio frequency signature

matching

ISSN : 1796-2021

Volume : 4 Issue : 2 Date : March 2009

Page(s): 96-107

Full Text: PDF (585 KB)

previously determined absolute reference position. The estimate is formulated from a combination

of the known speed, time and heading information with the known reference position. One of the

main obstacles to effective positioning of pedestrians via dead reckoning is the lack of accurate

speed estimation algorithms. Existing methods are either complex or provide results that are

unsatisfactory at the low velocities associated with pedestrians. In contrast, the two algorithms

proposed in this paper are relatively simple to implement and provide accurate results at low

velocities. In the first algorithm, 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 sense the same channel conditions (radio

frequency (RF) signature) previously observed at the leading antenna. Computer simulations show

that, with typical estimation errors of less than 2.67% around average pedestrian speeds, the

approach is indeed effective and accurate. A by-product of the algorithm is an environment specific

spatial correlation function which is used in the second algorithm to provide even better estimates.

With the improvements offered by the latter algorithm, relative errors of merely around 0.15% on

average are achievable. This improvement in performance over the first algorithm comes at the cost

of slightly higher computational complexity. When subsequently used for user displacement

estimation, a relatively small error of 24.5cm is observed after a duration of 60s.

matching