收稿日期: 2016-12-07
网络出版日期: 2018-12-24
基金资助
上海市科委基金资助项目(12511503303);上海市科委基金资助项目(14511105602);上海市科委基金资助项目(14511105902);上海大学特种光纤与光接入网重点实验室开放课题资助项目(SKLSFO2012-04);上海微系统所无线通信与传感器网络重点实验室开放课题资助项目
Time synchronization algorithm for UWSNs based on unidirectional broadcast mechanism of Chirp signal
Received date: 2016-12-07
Online published: 2018-12-24
水下无线传感器网络 (underwater wireless sensor networks,UWSNs) 的时间同步主要面临两大挑战,分别是水声传播时延较长和节点的移动性.针对水下无线传感器网络时间同步问题,提出了一种结合 Chirp 信号的单向广播机制的跨层时间同步 (Chirp-basedbroadcasting time synchronization, CB-Sync) 算法.CB-Sync 算法在物理层利用 Chirp 扩频信号的时钟频偏与相偏来减少因节点移动性带来的误差. 此外,CB-Sync 算法采用周期性的单向广播机制来同步邻居节点,邻居节点根据收到的广播信息,通过两次线性回归得到时钟的初始频偏与相偏,最后利用最小梯度下降算法来减少多普勒频移带来的误差,以提高最终的时间同步精度. 仿真实验结果表明,CB-Sync 算法具有更为高效的能量利用效率和时间同步精度.
金彦亮, 姚彬, 张晓帅 . 结合Chirp信号的单向广播机制水下无线传感器网络时间同步算法[J]. 上海大学学报(自然科学版), 2018 , 24(6) : 877 -887 . DOI: 10.12066/j.issn.1007-2861.1861
Time synchronization in mobile underwater wireless sensor networks (UWSNs) faces two major challenges, namely, long propagation delay and node mobility. In this paper, a Chirp-based broadcasting time synchronization (CB-Sync) algorithm based on unidirectional broadcast mechanism of a spread spectrum signal, i.e., Chirp, is proposed. The CB-Sync algorithm uses the clock frequency offset and phase offset of the Chirp at the physical layer to reduce errors caused by mobility of the nodes. Furthermore, CB-Sync algorithm uses a periodic one-way broadcast mechanism to synchronize neighboring nodes. According to the received broadcast information, the neighboring node obtains the initial frequency clock skew and offset by two linear regressions. Finally, a minimum gradient descent algorithm is used to reduce errors caused by Doppler shift to improve accuracy of time synchronization. Simulation results show that the CB-Sync algorithm can achieve higher energy efficient and better time synchronization accuracy.
| [1] | Liu J, Wang Z, Cui J H, et al. A joint time synchronization and localization design for mobile underwater sensor networks[J]. IEEE Transactions on Mobile Computing, 2016,15(3):530-543. |
| [2] | Chen K, Ma M, Cheng E, et al. A survey on MAC protocols for underwater wireless sensor networks[J]. IEEE Communications on Surveys & Tutorials, 2014,16(3):1433-1447. |
| [3] | Ganeriwal S, Srivastava M B. Timing-sync protocol for sensor networks [C]//Proc 1st ACM Conference on Embedded Network Sensor Systems. 2003: 138-149. |
| [4] | Maróti M, Kusy B, Simon G, et al. The flooding time synchronization protocol [C]// Proceedings of the 2nd International Conference on Embedded Networked Sensor Systems. 2004: 39-49. |
| [5] | Elson J, Girod L, Estrin D. Fine-grained network time synchronization using reference broadcasts[J]. ACM SIGOPS Operating Systems Review, 2002,36:147-163. |
| [6] | Heidemann J, Stojanovic M, Zorzi M. Underwater sensor networks: applications, advances and challenges[J]. Phil Trans R Soc A, 2012,370(1958):158-175. |
| [7] | Kebkal K G, Kebkal V K, Kebkal O G, et al. Underwater acoustic modems (S2CR Series) for synchronization of underwater acoustic network clocks during payload data exchange[J]. IEEE Journal of Oceanic Engineering, 2016,41(2):428-439. |
| [8] | 郭瑛, 张震. 大规模水下传感器网络时间同步研究[J]. 电子与信息学报, 2014,36(6):1498-1503. |
| [9] | Syed A A, Heidemann J S. Time synchronization for high latency acoustic networks [C]// Proceedings of the 25th IEEE Conference on Computer Communications (INFOCOM). 2006: 1-12. |
| [10] | Chirdchoo N, Soh W S, Chua K C. MU-Sync: a time synchronization protocol for underwater mobile networks [C]//Proceedings of the Third ACM International Workshop on Underwater Networks. 2008: 35-42. |
| [11] | Lu F, Mirza D, Schurgers C. D-sync: Doppler-based time synchronization for mobile underwater sensor networks [C]//Proceedings of the Fifth ACM International Workshop on UnderWater Networks. 2010: 3. |
| [12] | Liu J, Wang Z, Zuba M, et al. DA-Sync: a Doppler-assisted time-synchronization scheme for mobile underwater sensor networks[J]. IEEE Transactions on Mobile Computing, 2014,13(3):582-595. |
| [13] | 金彦亮, 方昌立, 姚彬. 结合啁啾信号的水下传感器网络时间同步算法[J]. 北京邮电大学学报, 2016(1):52-57. |
| [14] | Bahl P, Padmanabhan V N. RADAR: an in-building RF-based user location and tracking system [C]// Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies. 2000: 775-784. |
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