Reliable Line-of-Sight and Non-Line-of-Sight Propagation Channel Identification in Ultra-Wideband Wireless Networks

The paper addresses the problem of line-of-sight (LOS) vs. non-line-of-sight (NLOS) propagation link identification in ultra-wideband (UWB) wireless networks, which is necessary for improving the accuracy of radiolocation and positioning applications. A LOS/NLOS likelihood hypothesis testing approach is applied based on exploiting distinctive statistical features of the channel impulse response (CIR) using parameters related to the “skewness” of the CIR and its root mean square (RMS) delay spread. A log-normal fit is presented for the probability densities of the CIR parameters. Simulation results show that different environments (residential, office, outdoor, etc.) have measurable differences in their CIR parameters’ statistics, which is then exploited in determining the nature of the propagation channels. Correct LOS/NLOS channel identification rates exceeding 90% are shown to be achievable for most types of environments. Additional improvement is also obtained by combining both CIR skewness and RMS delay statistics.

• Mohamed Adnan Landolsi
• Ali F. Almutairi

• Ultra-wideband
• propagation
• line-of-sight
• non-line-of-sight
• identification.

[1] M. Benedetto et. al., “UWB communication systems: a comprehensive overview,” EURASIP Book Series on Signal Processing and Communications, vol.5, 2006, pp. 5-25.
[2] Z. Sahinoglu, S. Gezici and I. Guvenc, Ultra-Wideband Positioning Systems: Theoretical Limits, Ranging Algorithms and Protocols, CA: Cambridge University Press, 2008.
[3] H. Soganci, S. Gezici, H. Poor, “Accurate positioning in ultra-wideband systems,” IEEE Wireless Comm., vol.18, no.2, Feb. 2011, pp.19-27.
[4] I. Guvenc and C. Chong, “A Survey on TOA-based wireless localization and NLOS mitigation techniques,” IEEE Comm. Surveys & Tutorials, vol.11, no.3, March 2009, pp. 107-124.
[5] A. Abbasi and H. Liu, “Improved line-of-sight/non-line-of-sight classification methods for pulsed ultra-wideband localization,” IET Communications, vol. 8, no. 5, May 2014, pp. 680–688.
[6] S. Venkatesh and R. Buehrer, “Non-line-of-sight identification in ultra-wideband systems based on received signal statistics,” IET Microwaves, Antennas and Propagation, vol. 1, no. 6, June 2012, pp. 1120-1130.
[7] J. Khodjaev, Y. Park and A. Malik, “Survey of NLOS identification and error mitigation problems in UWB-based positioning algorithms for dense environments,” Annals of Telecom, vol.65, 2010, pp. 301-311.
[8] J. Zhang, J. Salmi, and E. S. Lohan, “Analysis of Kurtosis-based LOS/NLOS identification using indoor MIMO channel measurements,” IEEE Trans. on Vehic. Tech., vol. 62, no.7, July 2013, pp.2871-2874.
[9] L. Mucchi, and P. Marcocci, “A new parameter for UWB indoor channel profile identification,” IEEE Trans. Wireless Comm., vol. 8, Aug 2009, pp. 1597-1602.
[10] I. Guvenc, C.-C. Chong, F. Watanabe and H. Inomura, “NLOS identification and weighted least-square localization for UWB systems using multipath channel statistics”, EURASIP Jour. Adv. Signal Proc., vol.2008, Article ID 271984.
[11] A. Muqaibel, M.A. Landolsi, and N. Mahmoud, “Practical evaluation of NLOS/LOS parametric classification in UWB channels,” Proc. of Int. Conf. Com., Sig. Proc. App., DOI 10.1109/ICCSPA.2013.6487304.
[12] A. Molisch, “Ultra-wide-band propagation channels”, Proceedings of the IEEE, vol.97, no.2, Feb. 2009, pp. 353-371.
[13] A. Molish, K. Balakrishnan, C.-C. Chong, S. Emami, A. Fort, J. Karedal, H. Schantz, U. Schuster, and K. Siwiak, “IEEE 802.15.4a channel model-final report,” Tech. Rep., Environments, vol. 15, Sep. 2005, pp. 1-40.
[14] S. M. Kay, Fundamentals of Statistical Signal Processing, Vol. II: Detection Theory, Upper Saddle River, NJ: Prentice-Hall, 1998.