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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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TDoA-Based Practical Localization Using Precision Time-Synchronization

정밀 시각동기를 이용한 TDoA 기반의 위치 탐지

  • 김재완 (고려대학교 전자컴퓨터공학과 미래정보망 연구실) ;
  • 엄두섭 (고려대학교 전자컴퓨터공학과 미래정보망 연구실)
  • Received : 2012.09.06
  • Accepted : 2013.02.12
  • Published : 2013.02.28
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Abstract

The technology of precise time-synchronization between signal receive devices for separation distance operation can be a key point for the technology with TDoA-based system. We propose a new method for the higher accuracy of system's time-synchronization in this paper, which uses OCXO and DPLL with high accuracy to achieve phase synchronization at 1 pps (pulse per second) of signal. And the method receive time value from a GPS satellite. Essentially, the performance of GPS with high accuracy refers to long-term frequency stability for its reliability. As per the characteristic, as the GPS timing signals are synchronized continuously, the accuracy of time-synchronization gets improved proportionally. Therefore, if the time synchronization is accomplished, the accuracy of the synchronization can be up to 0.001 ppb (part per billion). Through the improved accuracy of the time-synchronization, the measurement error of TDOA-based location detection technology is evaluated. Consequently, we verify that TDoA-based location measurement error can be greatly improved via using the improved method for time-synchronization error.

신호수신장치들간 시각 동기화는 TDoA를 이용한 위치 탐지에 있어 가장 중요한 전제 사항이 된다. 본 논문에서는 시스템의 시각동기 정확도를 위하여 고정밀도의 OCXO와 DPLL을 이용하여 원자 클럭을 사용하는 GPS 위성으로부터 수신되는 1 pps(pulse per second) 신호에 위상동기 되는 방식을 제안한다. GPS 기반 고정밀 타이밍 레퍼런스의 성능은 근본적으로 매우 우수한 장기간에 걸친 주파수 안정도(long-term frequency stability)를 갖는 GPS 타이밍 신호의 특성을 따라간다고 볼 수 있으며, GPS 타이밍 신호에 동기가 되면 0.001 ppb(part per billion) 급의 초정밀 타이밍 레퍼런스를 통해 시각 동기의 정확도를 향상시킨다. 제안하는, 향상된 시각 동기 정확도를 통해 TDoA 기반의 위치 탐지 기술에서의 측정 오차를 평가하고, 시각동기 오차 개선 방법이 TDoA 기반의 위치 측정 오차를 크게 개선함을 보인다.

Keywords

References

  1. J. Elson and K. Romer, "Wireless sensor networks: a new regime for time synchronization," in Proc. Hot Topics In Networks (HotNets-I), pp. 149-154, Oct. 2002.
  2. S. Ganeriwal, R. Kumar, and M. B. Srivastava, "Timing-sync protocol for sensor networks," in Proc. ACM Conf. on Embed. Netw. Sensor Syst. (Sensys), pp. 138-149, 2003.
  3. M. L. Sichitiu and C. Veerarittiphan, "Simple, accurate time synchronization for wireless sensor networks," in Proc. IEEE Wirel. Commun. and Netw. Conf., (WCNC), pp. 1266-1273, Mar. 2003.
  4. J. Elson, L. Girod, and D. Estrin, "Fine-grained network time synchronization using reference broadcasts," in Proc. Operating Systems Design and Implementation (OSDI), pp. 147-163, Dec. 2002.
  5. S. Ganeriwal and M. Srivastava, "Timing-sync protocol for sensor networks," in Proc. ACM Conf. on Embed. Netw. Sensor Syst. (Sensys), pp. 138-149, 2003.
  6. S. Ganeriwal, I. Tsigkogiannis, and H. Shim, "Estimating clock uncertainty for efficient duty-cycling in sensor networks," IEEE/ACM Trans. on Netw., vol. 17 no. 3, pp. 843-856, Jun. 2009.
  7. B. Ai, Y. Shen, Z. D. Zhong, and B. H. Zhang, "Enhanced sampling clock offset correction based on time domain estimation scheme," IEEE Trans. Consum. Electr., vol. 57, no. 2, pp. 696-704, Apr. 2011. https://doi.org/10.1109/TCE.2011.5955210
  8. H. Kopetz and W. Schwabl, "Global time in distributed real-time systems," Technical Report 15/89, Technische Universitat Wien, Wien Austria, Oct. 1989.
  9. P. Ver1ssimo, L. Rodrigues, and A. Casimiro, "Cesiumspray: a precise and accurate global time service for large-scale systems," Technical report. NAV-TR-97-0001, Universidade de Lisboa, 1997.
  10. D. Mills, Z. Yang, and T. Marsland (Eds.), Internet Time Synchronization: the Network Time Protocol Global States and Time in Distributed Systems, IEEE Computer Society Press, 1991.
  11. H. T. Cho, H. S. Jang, and Y. J. Baek, "Practical localization system for consumer devices using zigbee networks," IEEE Trans. Consum. Electr., vol. 56, no. 3, pp. 696-704, Aug. 2010.
  12. T. P. Yunck, W. G. Melbourne, and C. L. Thoenton, "GPS-based satellite tracking system for precise positioning," IEEE Trans. Consum. Electr., vol. GE-23, no. 4, pp. 696-704, Jul. 1985.
  13. J. H. Han and D. K. Jeong, "Comparisons of error characteristics between TOA and TDOA positioning," IEEE Trans. Aero. and Elect Syst., vol. 38, no. 1, pp. 307-311, Jan. 2002. https://doi.org/10.1109/7.993253
  14. D. H. Shin and T. K. Sung, "Practical considerations in the design and implementation of time synchronization systems using IEEE 1588," IEEE Trans. Consum. Electr., vol. 47, no. 11, pp. 696-704, Nov. 2009.
  15. R. E. Kalman "A new approach to linear filtering and prediction problems," J. of Basic Engineering, no. 82, series. D, pp. 34-45, Mar. 1960.
  16. J. H. Hwang and M. S. Yoo, "The analysis on positioning error of recognition schemes of pilot signal in indoor TDoA positioning system using visible light communication", J. KICS, vol. 37B, no. 9, pp. 787-794, Sep. 2012. https://doi.org/10.7840/kics.2012.37B.9.787
  17. S. Y. Hwang and Y. S. Jung, Y. J. Back, "Reliable time synchronization protocol in sensor networks", J. KICS, vol. 31, no. 3A, pp. 274-281, Mar. 2006.
  18. W. H. Jang and Y. M. Kwon, "An improved time synchroniztion algorithm in sensor networks", J. The Institute of Electronics Engineers of Korea (IEEK), vol. 45, no. 9, pp. 13-19, Sep. 2008.

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