In this paper, a novel source localization scheme is proposed based on the unitary ESPRIT algorithm with back ray tracing technique and the city electronic maps. Our scheme can be summarized into two steps. First, the unitary ESPRIT algorithm is employed to estimate the angles and delays of the arrival rays radiated from the source. Second, based on the obtained information we devise a back ray tracing technique to recover the signal propagation paths according to the Geometrical Theory of Reflections and the city electronic map. After these two steps the source position can be obtained by averaging all the estimated positions. In order to minimize estimated errors caused by the Unitary ESPRIT, a valid-range selection criterion for the judgment of the validity of the estimated position data is proposed. On the other hand, we introduce a path length weighting factor to reduce the estimated errors caused by the terrain data inaccuracy. This position method can locate both the line of sight (LOS) and non-line of sight (NLOS) sources efficiently and it also can locate multi-sources simultaneously. Six simulations are carried out in three terrain scenarios. The numerical results demonstrate that our model can be applied to estimate the positions for both 2D and 3D cases. The accuracy of our model for a cell of 80 m × 45 m can reach 10 m when SNR is greater than 10 dB.
1. Tayebi, A., J. Gόmez, F. S. Saez De Adana, and O. Gutierrez, "The application of ray-tracing to mobile localization using the direction of arrival and received signal strength in multipath indoor environments," Progress In Electromagnetic Research, Vol. 91, 1-15, 2009. doi:10.2528/PIER09020301
2. Soliman, M. S., T. Morimoto, and Z. I. Kawasaki, "Three-dimensional localization system for impulsive noise sources using ultra-wideband digital interferometer technique," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 4, 515-530, 2006. doi:10.1163/156939306776117027
3. Soliman, M. S., A. Hirata, T. Morimoto, and Z. I. Kawasaki, "Numerical and experimental study on three-dimensional localization for ultra-wideband impulsive noise sources," Journal of Electromagnetic Waves and Applications, Vol. 19, No. 2, 175-187, 2005. doi:10.1163/1569393054497276
4. Liew, S. C., K. G. Tan, and C. P. Tan, "Non-taylor series based positioning method for hybrid GPS/cellphone system," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 6, 717-729, 2006. doi:10.1163/156939306776143451
5. Liew, S. C., K. G. Tan, and T. S. Lim, "Investigation of direct A-GPS positioning for hybrid E-OTD/GNSS," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 1, 79-87, 2006. doi:10.1163/156939306775777332
6. Chueng, K. W., H. C. So, W.-K. Ma, and Y. T. Chan, "Least square algorithms for time-of-arrival based mobile location," IEEE Trans. Signal Processing, Vol. 52, 1121-1128, 2004. doi:10.1109/TSP.2004.823465
7. Wang, X., Z. X. Wang, and B. O. Dea, "A TOA based location algorithm reducing the errors due to Nom-Line-of-Sight (NLOS) propagation," IEEE Trans. Veh. Tech., Vol. 52, 112-116, 2003. doi:10.1109/TVT.2002.807158
8. Ca®ery, J. J., "Wireless Location in CDMA Cellular Radio Systems," KAP, 1999.
9. Landesa, L., I. T. Castro, J. M. Taboada, and F. Obelleiro, "Bias of the maximum likelihood DOA estimation from inaccurate knowledge of the antenna array response," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 9, 1205-1217, 2007.
10. Harabi, F., H. Changuel, and A. Gharsallah, "Direction of arrival estimation method using a 2-L shape arrays antenna," Progress In Electromagnetics Research, Vol. 69, 145-160, 2007. doi:10.2528/PIER06120204
11. Deng, P. and P. Z. Fan, "An AOA assisted TOA position system," ICCT 2000 Proceedings, 1501-1504, Beijing, 2000.
12. Cong, L. and W. H. Zhuang, "Hybrid TDOA/AOA mobile users location for wideband CDMA cellular system," IEEE Trans. Wireless Commun., Vol. 1, 439-447, 2002. doi:10.1109/TWC.2002.800542
13. Cong, L. and W. H. Zhuang, "Non-line-sight error mitigation in mobile location," IEEE Trans. Wireless Commun., Vol. 4, 560-572, 2005. doi:10.1109/TWC.2004.843040
14. Chen, P. C., "A non-line-of-sight error mitigation algorithm in location estimation," Proc. IEEE Wireless Communications Networking Conf., Vol. 1, 316-320, 1999.
15. Chan, Y. T., W. Y. Tsui, H. C. So, and P. C. Ching, "Time-of-arrival based localization under NLOS conditions," IEEE Trans. Veh. Tech., Vol. 55, 17-24, 2006. doi:10.1109/TVT.2005.861207
16. Algeier, V., B. Demissie, W. Koch, and R. Thomae, "Blind localization of 3G mobile terminals in multipath scenarios," Proceedings of the 3rd Workshop on Position and Communication, 219-226, 2006.
17. Kikuchi, S., A. Sano, H. Tsuji, and R. Miura, "A novel approach to mobile-terminal positioning using signal array antenna in urban environments," Proc. VTC IEEE, 1010-1014, 2003.
18. Seow, C. K. and S. Y. Tan, "Localization of omni-directional mobile device in multipath environments," Progress In Electromagnetic Research, Vol. 85, 323-348, 2008. doi:10.2528/PIER08090302
19. Teh, C. H., F. Kung, and H. T. Chuah, "A path-corrected wall model for ray-tracing propagation modeling," Journal of Electromagnetic Waves and Application, Vol. 20, No. 2, 207-214, 2006. doi:10.1163/156939306775777288
20. Jin, K.-S., T. I. Suh, S. H. Suk, B. C. Kim, and H. T. Kim, "Fast ray tracing using a space-division algorithm for RCS prediction," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 1, 119-126, 2006. doi:10.1163/156939306775777341
21. Haardt, M. and J. A. Nossek, "Unitary ESPRIT: How to obtain increased estimation accuracy with a reduced computational burden," IEEE Trans. Signal Processing, Vol. 43, 1232-1242, 1995. doi:10.1109/78.382406
22. Haardt, M. and J. A. Nossek, "Simultaneous schur decomposition of several nonsymmetric matrices to achieve automatic pairing in multidimensional harmonic retrieval problems," IEEE Trans. Signal Processing, Vol. 44, 161-169, 1998. doi:10.1109/78.651206
23. Xu, G., H. R. Richard, and T. Kailath, "Detection of number of sources via exploitation of centro-symmetry Property," IEEE Trans. Signal Processing, Vol. 42, 102-112, 1994. doi:10.1109/78.258125
24. Lee, A., "Centrohermitian and skew-centrohermitian matrices," Linear Algebra Applicat., Vol. 48, 198-212, 1994.
25. Zoltowski, M. D., M. Haardt, and C. P. Mathews, "Closed-form 2D angle estimation with rectangle arrays in element space or beamspace via unitary ESPRIT," IEEE Trans. Signal Proceeding, Vol. 44, 316-329, J. A. Nossek, Ed., 1996. doi:10.1109/78.485927
26. Haardt, M., Effiient One-, Two- and Multidimensional High-Resolution Array Signal Proceeding, Aache, Shaker Verlag, Germany, 1996.
27. Zwick, T., D. Hampicke, A. Richter, G. Sommerkorn, R. Thoma, and W. Wisebeck, "A novel antenna concept for double-directional channel measurements," IEEE Trans. Veh. Tech., Vol. 53, 527-537, 2004. doi:10.1109/TVT.2004.823529
28. Wax, M. and T. Kailath, "Detection of signal by information theoretic criteria," IEEE Trans. on Acoustics, Speech, and Signal Processing, Vol. 33, 387-392, 1985. doi:10.1109/TASSP.1985.1164557
29. Chen, S. H. and S. K. Jeng, "An SBR/image approach for radio wave propagation in indoor environments with metallic furniture," IEEE Trans. Antennas Propagrat., Vol. 45, No. 1, 98-106, 1997. doi:10.1109/8.554246
30. Har, D., H. H. Xia, and H. L. Bertoni, "Path-loss prediction model for microcells," IEEE Trans. Veh. Tech., Vol. 18, No. 5, 1453-1462, 1999. doi:10.1109/25.790520
31. Liang, G. and H. L. Bertoni, "A new approach to 3-D ray tracing for propagation prediction in cities," IEEE Trans. Antennas Propagrat., Vol. 46, No. 6, 853-863, 1998. doi:10.1109/8.686774
32. Ni, H., G. Ren, and Y. Chang, "A TDOA location scheme in OFDM based WMANs," IEEE Transactions on Consumer Electronics, Vol. 54, No. 3, 1017-1021, 2008. doi:10.1109/TCE.2008.4637581
33. Kaemarungsi, K. and P. Krishnamurthy, "Modeling of indoor positioning systems based on location fingerprinting," Proceedings of the 23th Annual Joint Conference of the IEEE Computer and Communications Societies, Vol. 2, 1012-1022, Hong Kong, 2004.
34. Ahonen, S. and P. Eskelinen, "Mobile terminal location for UMTS," IEEE Aerospace and Electronic Systems Magazine, Vol. 18, No. 2, 23-27, 2003. doi:10.1109/MAES.2003.1183866
35. Proakis, J. G. and M. Salehi, Communication Systems Engineering, 2 Ed., Publishing House of Electronics Industry, Beijing, 2007.