27-06-2012, 12:35 PM
Time of Arrival Estimation for WLAN Indoor Positioning Systems using
Matrix Pencil Super Resolution Algorithm
[attachment=25716]
Abstract
The accuracy of prediction of time of arrival (TOA) in wireless local area
networks (WLAN) is the most important parameter for indoor positioning systems. This
paper presents the application of super resolution matrix pencil (MP) algorithm for
TOA estimation for indoor positioning application. Also it presents the results of
frequency sweep measurements of indoor channel for the WLAN IEEE 801.11
standards (a, b, and g ). The simulation and experimental results show that MP can
accurately estimate TOA and has superior performance over the Fourier transform
technique. Also the computational complexity of the proposed technique is compared
with the ESPRIT and root-MUSIC algorithms.
Introduction
The positioning systems that are used to track and determine the users have gained increasing
interest. A Global Positioning System (GPS) is a typical example which depends on the
received signal from multiple satellites. In indoor location systems GPS is not efficient due to
obstruction and shielding of satellite signals. Also there are cellular networks base wide area
location systems, which are limited by the cell size. In indoor environment, there are many
positioning systems based on different technologies such as ultrasound [1], Infrared [2], video
surveillance and the systems that depend on received signal strength [3].
Simulation Results
To demonstrate the performance of MP algorithm in TOA estimation for WLAN indoor
positioning application, extensive simulations were performed. Comparison of the proposed
algorithm with the conventional inverse Fourier transform (IFT) is presented. The complex
frequency response was calculated by simulating the indoor WLAN channel. Fig.2 shows
the normalized time domain channel impulse responses obtained from frequency swept data
in the range 2.4 to 2.48 GHz (IEEE801.11b WLAN standard). In this situation which appear
in limited bandwidth systems makes it impossible to distinguish the DLOS path using the
conventional IFT technique. It shows the ability of MP for detecting DLOS path, which
correspond to the TOA.
Measurement System and Experimental Results
One of the most popular techniques to experimentally calculate the TOA is through the use of
a frequency domain measurement system using Vector Network Analyzer (VNA). The main
component of the measurement system used is an Anritsu-Wiltron 37347A network analyzer.
The complex frequency channel response can be obtained by sweeping the channel at
uniformly spaced frequencies. The forward transmission scattering coefficient S21 (the
complex channel frequency response) is measured. The system is depicted in the block
diagram of Fig.5.
Conclusions
In this paper, MP algorithm has been applied to complex frequency response to perform TOA
estimation for indoor positioning application. Extensive measurements of frequency responses
for IEEE801.11 WLAN standards (a,b and g) have been done. The simulation and
experimental results outperform the high resolution of the algorithm. The results show that
MP have better performance than conventional IFT techniques. Also the computation
performance of MP is found to be better than that of ESPRIT and MUSIC super resolution
algorithms.
PROCEEDINGS OF THE 2nd WORKSHOP ON POSITIONING, NAVIGATION AND COMMUNICATION (WPNC’05)
& 1st ULTRA-WIDEBAND EXPERT TALK (UET'05)
Matrix Pencil Super Resolution Algorithm
[attachment=25716]
Abstract
The accuracy of prediction of time of arrival (TOA) in wireless local area
networks (WLAN) is the most important parameter for indoor positioning systems. This
paper presents the application of super resolution matrix pencil (MP) algorithm for
TOA estimation for indoor positioning application. Also it presents the results of
frequency sweep measurements of indoor channel for the WLAN IEEE 801.11
standards (a, b, and g ). The simulation and experimental results show that MP can
accurately estimate TOA and has superior performance over the Fourier transform
technique. Also the computational complexity of the proposed technique is compared
with the ESPRIT and root-MUSIC algorithms.
Introduction
The positioning systems that are used to track and determine the users have gained increasing
interest. A Global Positioning System (GPS) is a typical example which depends on the
received signal from multiple satellites. In indoor location systems GPS is not efficient due to
obstruction and shielding of satellite signals. Also there are cellular networks base wide area
location systems, which are limited by the cell size. In indoor environment, there are many
positioning systems based on different technologies such as ultrasound [1], Infrared [2], video
surveillance and the systems that depend on received signal strength [3].
Simulation Results
To demonstrate the performance of MP algorithm in TOA estimation for WLAN indoor
positioning application, extensive simulations were performed. Comparison of the proposed
algorithm with the conventional inverse Fourier transform (IFT) is presented. The complex
frequency response was calculated by simulating the indoor WLAN channel. Fig.2 shows
the normalized time domain channel impulse responses obtained from frequency swept data
in the range 2.4 to 2.48 GHz (IEEE801.11b WLAN standard). In this situation which appear
in limited bandwidth systems makes it impossible to distinguish the DLOS path using the
conventional IFT technique. It shows the ability of MP for detecting DLOS path, which
correspond to the TOA.
Measurement System and Experimental Results
One of the most popular techniques to experimentally calculate the TOA is through the use of
a frequency domain measurement system using Vector Network Analyzer (VNA). The main
component of the measurement system used is an Anritsu-Wiltron 37347A network analyzer.
The complex frequency channel response can be obtained by sweeping the channel at
uniformly spaced frequencies. The forward transmission scattering coefficient S21 (the
complex channel frequency response) is measured. The system is depicted in the block
diagram of Fig.5.
Conclusions
In this paper, MP algorithm has been applied to complex frequency response to perform TOA
estimation for indoor positioning application. Extensive measurements of frequency responses
for IEEE801.11 WLAN standards (a,b and g) have been done. The simulation and
experimental results outperform the high resolution of the algorithm. The results show that
MP have better performance than conventional IFT techniques. Also the computation
performance of MP is found to be better than that of ESPRIT and MUSIC super resolution
algorithms.
PROCEEDINGS OF THE 2nd WORKSHOP ON POSITIONING, NAVIGATION AND COMMUNICATION (WPNC’05)
& 1st ULTRA-WIDEBAND EXPERT TALK (UET'05)