Browse > Article

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

Ma, Lin Chuan (인하대학교 정보통신대학원 무전전송연구실)
Hwang, Jae-Ho (인하대학교 정보통신대학원 무전전송연구실)
Choi, Nack-Hyun (인하대학교 정보통신대학원 무전전송연구실)
Kim, Jae-Moung (인하대학교 정보통신대학원 무전전송연구실)
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
Ultra-wideband; NLOS Identification; Energy Capture; Adaptive Modulation; CIR;
Citations & Related Records
연도 인용수 순위
  • Reference
1 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
2 I. Guvenc; Chong Chia-Chin; F. Watanabe; 'NLOS identification and mitigation for UWB localization systems'; Wireless Communications and Networking Conference, 2007. IEEE
3 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
4 M. Tuchler and A. Huber; 'An improved algorithm for UWB-based positioning in a multipath environment'; International Zurich Seminar on Communications, Zurich, Switzerland, 2006
5 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
6 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   DOI   ScienceOn
7 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   DOI   ScienceOn
8 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
9 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
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 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
12 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   DOI   ScienceOn
13 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
14 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