【摘要】：時(shí)間同步是無(wú)線傳感器網(wǎng)絡(luò)（Wireless Sensor Network，WSN）的一項(xiàng)關(guān)鍵技術(shù)，它為分布式系統(tǒng)提供了一個(gè)共同的時(shí)間基準(zhǔn)，在數(shù)據(jù)融合、功率管理、傳輸調(diào)度、定位跟蹤等方面都具有重要意義。因此，時(shí)間同步已成為研究的熱點(diǎn)話題之一。 無(wú)線傳感器網(wǎng)絡(luò)部署之后，網(wǎng)絡(luò)的壽命很大程度上取決于電池的壽命。在實(shí)際無(wú)線傳感器網(wǎng)絡(luò)中，通常節(jié)點(diǎn)不易收回，因此能源是一種稀缺資源。能量效率是設(shè)計(jì)無(wú)線傳感器網(wǎng)絡(luò)時(shí)間同步協(xié)議時(shí)應(yīng)該優(yōu)先考慮的主要因素，因此本文深入研究了低能耗的時(shí)間同步問(wèn)題。本文的主要工作如下： （1）分析了無(wú)線傳感器網(wǎng)絡(luò)時(shí)間同步技術(shù)的國(guó)內(nèi)外研究現(xiàn)狀和時(shí)間同步的基本理論，對(duì)目前經(jīng)典的時(shí)間同步算法進(jìn)行了分析與比較，為后續(xù)的研究提供了理論基礎(chǔ)。 （2）運(yùn)用最大似然估計(jì)原理，提出了一種時(shí)鐘頻率偏移補(bǔ)償方法。針對(duì)現(xiàn)有的基于發(fā)送端接收端雙向時(shí)間同步的模型（例如TPSN算法等），都未考慮時(shí)鐘頻率偏移補(bǔ)償問(wèn)題，導(dǎo)致同步精度較低。本文通過(guò)將網(wǎng)絡(luò)延遲建模為指數(shù)延遲模型，并對(duì)雙向交換中第一個(gè)和最后一個(gè)的同步信標(biāo)分組的時(shí)間戳進(jìn)行采樣，計(jì)算出時(shí)鐘頻率偏移和時(shí)鐘偏移，提高了時(shí)間同步精度，延長(zhǎng)了同步周期。 （3）針對(duì)時(shí)間同步中的時(shí)間間隔、節(jié)點(diǎn)間雙向同步時(shí)交換的同步信標(biāo)數(shù)目、以及同步模式的選擇等問(wèn)題，提出了一種低能耗的多跳自適應(yīng)時(shí)間同步算法（MATS：Multi-hop Adaptive Time Synchronization）。該算法設(shè)計(jì)了一套靈活的機(jī)制來(lái)調(diào)整同步模式、全網(wǎng)重同步周期以及每對(duì)節(jié)點(diǎn)同步時(shí)的信標(biāo)數(shù)，，并給出了對(duì)應(yīng)的量化模型，同時(shí)對(duì)節(jié)點(diǎn)的時(shí)鐘頻率偏移和時(shí)鐘偏移進(jìn)行估計(jì)，實(shí)現(xiàn)了用較小的能量損耗完成長(zhǎng)期的、全網(wǎng)的時(shí)間同步的目標(biāo)。 （4）對(duì)上述提出的MATS算法在同步精度和能耗方面的影響因素進(jìn)行了分析，并給出了幾種主要節(jié)能策略。同時(shí)，對(duì)MATS算法的同步誤差和能量消耗與TPSN算法進(jìn)行了實(shí)驗(yàn)比較，理論與仿真結(jié)果表明：MATS算法在同步精度和同步能耗上都是優(yōu)于TPSN算法的。 對(duì)時(shí)間同步協(xié)議的設(shè)計(jì)是需要考慮實(shí)際應(yīng)用的。本文提出的時(shí)間同步算法主要是針對(duì)環(huán)境監(jiān)測(cè)的應(yīng)用，對(duì)于其他低功耗的應(yīng)用需求，本文所采用的方法和思想也具有一定的借鑒意義。
[Abstract]:Time synchronization is a key technology in wireless sensor networks (Wireless Sensor Network,WSN). It provides a common time benchmark for distributed systems, in data fusion, power management, transmission scheduling, Location and tracking are of great significance. Therefore, time synchronization has become one of the hot topics. After the deployment of wireless sensor networks, the lifetime of the network depends to a great extent on the battery life. In practical wireless sensor networks, nodes are often difficult to recover, so energy is a scarce resource. Energy efficiency is the main factor that should be considered in the design of time synchronization protocol in wireless sensor networks. Therefore, the low energy consumption time synchronization problem is studied in this paper. The main work of this paper is as follows: (1) the research status and the basic theory of time synchronization in wireless sensor networks are analyzed, and the classical time synchronization algorithms are analyzed and compared. It provides a theoretical basis for further research. (2) using the principle of maximum likelihood estimation, a clock frequency offset compensation method is proposed. For the existing bidirectional time synchronization models based on the transmitter receiver (such as TPSN algorithm), the clock frequency offset compensation is not considered, which leads to low synchronization accuracy. In this paper, the network delay is modeled as exponential delay model, and the time stamp of the first and last synchronous beacon packets in bidirectional switching is sampled, the clock frequency offset and clock offset are calculated, and the precision of time synchronization is improved. The synchronization period is extended. (3) aiming at the time interval in time synchronization, the number of synchronous beacons exchanged between nodes, and the choice of synchronization mode. A low energy consumption adaptive time synchronization algorithm (MATS:Multi-hop Adaptive Time Synchronization).) is proposed. The algorithm designs a set of flexible mechanisms to adjust the synchronization mode, the whole network resynchronization period and the number of beacons in each pair of nodes synchronization, and gives the corresponding quantization model. At the same time, the clock frequency offset and clock offset of the node are estimated. The goal of long-term, whole-network time synchronization is achieved with small energy loss. (4) the factors affecting the synchronization accuracy and energy consumption of the proposed MATS algorithm are analyzed, and several main energy-saving strategies are given. At the same time, the synchronization error and energy consumption of the MATS algorithm are compared with the TPSN algorithm. The theoretical and simulation results show that the MATS algorithm is superior to the TPSN algorithm in synchronization accuracy and energy consumption. The design of time synchronization protocol needs to consider the practical application. The time synchronization algorithm proposed in this paper is mainly aimed at the application of environmental monitoring. For other low-power applications, the methods and ideas used in this paper also have some reference significance.
【學(xué)位授予單位】：重慶理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TP212.9;TN929.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 田賢忠;陳登;胡同森;;無(wú)線傳感器網(wǎng)絡(luò)按需時(shí)間同步算法研究[J];傳感技術(shù)學(xué)報(bào);2008年11期

2 吳寶明;李聲飛;;基于最優(yōu)線性擬合的WSN時(shí)間同步算法研究[J];傳感技術(shù)學(xué)報(bào);2010年12期

3 孫新偉;申興發(fā);張能貴;;無(wú)線傳感器網(wǎng)絡(luò)節(jié)點(diǎn)周期性休眠時(shí)間同步研究[J];機(jī)電工程;2010年05期

4 肖琳;程利娟;王福豹;;一種低功耗無(wú)線傳感器網(wǎng)絡(luò)時(shí)間同步算法[J];計(jì)算機(jī)研究與發(fā)展;2008年01期

5 徐朝農(nóng);徐勇軍;李曉維;;無(wú)線傳感器網(wǎng)絡(luò)時(shí)間同步新技術(shù)[J];計(jì)算機(jī)研究與發(fā)展;2008年01期

6 鄧亞平;王旭;;低功耗無(wú)線傳感器網(wǎng)絡(luò)時(shí)間同步方法[J];計(jì)算機(jī)工程與應(yīng)用;2011年06期

7 沈明玉;艾治雄;;無(wú)線傳感網(wǎng)絡(luò)低能耗時(shí)間同步的研究[J];計(jì)算機(jī)工程與應(yīng)用;2012年08期

8 夏小鳳;嚴(yán)斌宇;劉方圓;盧葦;;無(wú)線傳感器網(wǎng)絡(luò)TPSN的優(yōu)化算法[J];計(jì)算機(jī)測(cè)量與控制;2010年06期

9 任豐原,黃海寧,林闖;無(wú)線傳感器網(wǎng)絡(luò)[J];軟件學(xué)報(bào);2003年07期

10 王福豹,史龍,任豐原;無(wú)線傳感器網(wǎng)絡(luò)中的自身定位系統(tǒng)和算法[J];軟件學(xué)報(bào);2005年05期

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