The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
권호 표지

Adaptive Modulation Method using Non-Line-of-Sight Identification Algorithm in LDR-UWB Systems

  • 마림천 (인하대학교 정보통신대학원 무전전송연구실) ;
  • 황재호 (인하대학교 정보통신대학원 무전전송연구실) ;
  • 최낙현 (인하대학교 정보통신대학원 무전전송연구실) ;
  • 김재명 (인하대학교 정보통신대학원 무전전송연구실)
  • Published : 2008.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Non-line-of-sight (NLOS) propagation can severely weaken the accuracy of ranging and localization in wireless location systems. NLOS bias mitigation techniques have recently been proposed to relieve the NLOS effects, but positively rely on the capability to accurately distinguish between LOS and NLOS propagation scenarios. This paper proposes an energy-capture-based NLOS identification method for LDR-UWB systems, based on the analysis of the characteristics of the channel impulse response (CIR). With this proposed energy capture method, the probability of successfully identifying NLOS is much improved than the existing methods, such as the kurtosis method, the strongest path compare method, etc. This NLOS identification method can be employed in adaptive modulation scheme to decrease bit error ratio (BER) level for certain signal-to-noise ratio (SNR). The BER performance with the adaptive modulation can be significantly enhanced by selecting proper modulation method with the knowledge of channel information from the proposed NLOS identification method.

Keywords

References

  1. M. Z. Win and R. A. Scholtz; 'On the robustness of ultra-wideband signals in dense multipath environments'; IEEE Communication Letters, Vol.2, No.2, pp.51-53,1998 https://doi.org/10.1109/4234.660801
  2. M. Z. Win and R. A. Scholtz; 'Characterization of ultra-wide bandwidth wireless indoor channels: a communication-theoretic view'; IEEE Journal on Selected Areas in Communications, Vol.20, No.9, pp.1633-1627, 2002
  3. D.Cassioli, M. Z. Win, and A. F. Monlisch; 'The ultra-wide bandwidth indoor channel: from statistical model to simulations'; IEEE Journal on Selected Areas in Communications, Vol.20, No.6, pp.1247-1257, 2002 https://doi.org/10.1109/JSAC.2002.801228
  4. A. F. Monlisch, D. Cassioli, C.-C. Chong, et al.; 'A comprehensive standardized model for ultrawideband propagation channels'; IEEE Transaction on Antannas and Propagation, Vol. 54, No.11, pp.3151-3166, 2006 https://doi.org/10.1109/TAP.2006.883983
  5. J. Borras; P. Hatrack; N.B. Mandayam; 'Decision theoretic framework for NLOS identification'; 1998 Vehicular Technology Confe-rence, (VTC 98), May 1998, Vol.2, pp.1583-1587. 48th IEEE
  6. L. Cong; Zhuang Weihua; 'Non-line-of-sight error mitigation in TDOA mobile location'; in Proc. IEEE conference on computer communications (INFOCOM), Hong Kong, Ma. 2004, pp.650-659
  7. S.Gezici, H.Kobayashi, and H.V.Poor; 'Non-parametric non-light-of-sight identification'; Proc. IEEE Vehic Technol. Conference. (VTC), Vol.4, Orlando, FL, Otc.2003, pp.2544-2548
  8. A. Rabbachin; I. Oppermann; B. Denis; 'ML Time-of-Arrival estimation based on low complexity UWB energy detection'; in Proc. IEEE International Conference on Ultrawideband (ICU- WB), Waltham, MA, Sept. 2006, pp.598-604
  9. I. Guvenc; Chong Chia-Chin; F. Watanabe; 'NLOS identification and mitigation for UWB localization systems'; Wireless Communications and Networking Conference, 2007. IEEE
  10. N. J. August, R. Thirugnanam, Ha Dong Sam; 'An adaptive modulation scheme for optimization of energy, BER, and data rate'; Joint with Conference on Ultrawideband Systems and Technologies, 2004. pp.182-186
  11. A.F. Molisch, K. Balakrishnan, D. Cassioli, et al.: 'IEEE 802.15.4a channel model - final report'; Technical Report, IEEE 802.15-01-1662-01- 04a, September 2004
  12. M. Tuchler and A. Huber; 'An improved algorithm for UWB-based positioning in a multipath environment'; International Zurich Seminar on Communications, Zurich, Switzerland, 2006
  13. R. Caas, A. Marco, J.J. Guerrero, and H. Falco; 'Robust Estimator for Non-Line-of-Sight Error Mitigation in Indoor localization' Eurasip J. Applied Sig. Processing, pp.1-8, 2006
  14. Chin-Der Wann; Chih-Sheng Hsueh; 'NLOS mitigation with biased kalman filters for range estimation in UWB systems' TENCON 2007 - 2007 IEEE Region 10 Conference