本文選題：精準(zhǔn)農(nóng)業(yè) + 軟件無(wú)線電�。� 參考：《北京郵電大學(xué)》2015年碩士論文

【摘要】：如何在有限的農(nóng)業(yè)資源基礎(chǔ)上,提高農(nóng)業(yè)的生產(chǎn)效率、經(jīng)濟(jì)效益與環(huán)境效益已經(jīng)成為我國(guó)農(nóng)業(yè)精細(xì)化進(jìn)程所必須要解決的問題。依托先進(jìn)的信息技術(shù)成為實(shí)現(xiàn)這一目標(biāo)的重要手段。在眾多的信息化技術(shù)中無(wú)線傳感器網(wǎng)絡(luò)技術(shù)無(wú)疑是農(nóng)業(yè)現(xiàn)代化研究最熱門的方向之一。 無(wú)線傳感器網(wǎng)絡(luò)技術(shù)包括了傳感器技術(shù)、微機(jī)電系統(tǒng)技術(shù)、無(wú)線通信技術(shù)、嵌入式計(jì)算技術(shù)和分布式信息處理技術(shù),它們具有功耗低的特點(diǎn)。也正是由于低功耗使得節(jié)點(diǎn)間的收發(fā)不像傳統(tǒng)的無(wú)線通信一樣可以覆蓋較大的范圍,當(dāng)應(yīng)用環(huán)境不一樣時(shí),無(wú)線傳感器網(wǎng)絡(luò)的覆蓋特性會(huì)有很大的不同。 農(nóng)業(yè)環(huán)境具有地勢(shì)多樣、天氣狀況復(fù)雜、面積龐大、農(nóng)作物生長(zhǎng)周期長(zhǎng)等特點(diǎn),這些特點(diǎn)給無(wú)線傳感器網(wǎng)絡(luò)技術(shù)的應(yīng)用帶來(lái)了挑戰(zhàn)。在實(shí)際環(huán)境下部署無(wú)線傳感器網(wǎng)絡(luò)前需要對(duì)信號(hào)的傳播環(huán)境有細(xì)致的了解，，才能保證網(wǎng)絡(luò)的覆蓋性�；谶@點(diǎn),本文從兩個(gè)角度來(lái)分析測(cè)量農(nóng)田環(huán)境下信號(hào)的傳播特性。第一,我們使用無(wú)線傳感器節(jié)點(diǎn)和頻譜儀測(cè)量冬小麥在三種典型的生長(zhǎng)期下433MHz信號(hào)的路徑損耗變化特性,整個(gè)測(cè)量工作在國(guó)家精準(zhǔn)化農(nóng)業(yè)基地完成,完成測(cè)量工作之后,利用matlab對(duì)所得數(shù)據(jù)進(jìn)行曲線擬合和回歸分析,得出農(nóng)業(yè)環(huán)境下433MHz信號(hào)的大尺度傳播模型,然后將所得模型與我們?cè)谑覂?nèi)和室外空曠環(huán)境測(cè)量總結(jié)的模型進(jìn)行比較,分析麥田環(huán)境對(duì)信號(hào)傳播特征的影響；第二,使用軟件無(wú)線電平臺(tái)GNU Radio和USRP設(shè)計(jì)多徑時(shí)延特性測(cè)量系統(tǒng),系統(tǒng)由兩臺(tái)USRP組成,發(fā)送端發(fā)送M序列,接收端利用相同的M序列對(duì)接收信號(hào)進(jìn)行滑動(dòng)相關(guān)處理,提取相關(guān)后信號(hào)的功率延遲分布,通過功率延遲分布得到信號(hào)的多徑時(shí)延和多徑強(qiáng)度。在完成系統(tǒng)設(shè)計(jì)后,在北京郵電大學(xué)校園內(nèi)進(jìn)行了室外LOS和NLOS測(cè)試,得到兩種信道條件下433MHz無(wú)線信號(hào)的功率延遲分布,利用功率延遲分布得到該環(huán)境下信號(hào)的多徑傳播特性,驗(yàn)證了測(cè)量系統(tǒng)的有效性。
[Abstract]:How to improve agricultural production efficiency, economic benefit and environmental benefit on the basis of limited agricultural resources has become a problem that must be solved in the process of agricultural refinement in China.Relying on advanced information technology has become an important means to achieve this goal.Wireless sensor network (WSN) is one of the hottest research directions in agricultural modernization.Wireless sensor network technology includes sensor technology, MEMS technology, wireless communication technology, embedded computing technology and distributed information processing technology, which have the characteristics of low power consumption.Because of the low power consumption, the transceiver between nodes can not cover a large range like traditional wireless communication. When the application environment is different, the coverage characteristics of wireless sensor networks will be very different.The agricultural environment has the characteristics of diverse terrain, complex weather conditions, huge area and long crop growth cycle. These characteristics have brought challenges to the application of wireless sensor network (WSN) technology.In order to ensure the coverage of wireless sensor networks, it is necessary to have a detailed understanding of the signal propagation environment before deploying wireless sensor networks in the actual environment.Based on this, this paper analyzes the signal propagation characteristics in the field environment from two angles.First, we use wireless sensor nodes and spectrometers to measure the path loss characteristics of winter wheat 433MHz signals during three typical growth periods. The whole measurement was completed at the National Precision Agriculture Base.By using matlab curve fitting and regression analysis, the large scale propagation model of 433MHz signal in agricultural environment was obtained, and then the model was compared with the model that we summarized in indoor and outdoor open environment.The effects of wheat field environment on the signal propagation characteristics are analyzed. Secondly, a multi-path delay measurement system is designed using the software radio platforms GNU Radio and USRP. The system is composed of two USRP, and the transmitter transmits M sequence.The receiver uses the same M sequence to carry on the sliding correlation processing to the received signal, extracts the power delay distribution of the correlated signal, and obtains the multipath delay and the multipath intensity of the signal by the power delay distribution.After completing the system design, outdoor LOS and NLOS tests were carried out on the campus of Beijing University of posts and Telecommunications. The power delay distribution of 433MHz wireless signals was obtained under two channel conditions. The multipath propagation characteristics of the signals in this environment were obtained by using the power delay distribution.The validity of the measurement system is verified.
【學(xué)位授予單位】：北京郵電大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：S126;TN92

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 曹瀚文;王文博;;GNU Radio:開放的軟件無(wú)線電平臺(tái)[J];電信快報(bào);2007年04期

2 谷歆海;;網(wǎng)絡(luò)分析儀的工作原理及在測(cè)量領(lǐng)域的應(yīng)用[J];電子工程師;2008年07期

3 王代華;宋林麗;孔祥善;張志杰;;草原環(huán)境地表無(wú)線信道的路徑損耗建模[J];光學(xué)精密工程;2012年06期

4 鄭翔;岳浩嶺;;嵌入式Linux系統(tǒng)下CC1101的驅(qū)動(dòng)與應(yīng)用[J];單片機(jī)與嵌入式系統(tǒng)應(yīng)用;2014年02期

5 李太浩;潘賀;;基于不同種植密度的玉米大田環(huán)境無(wú)線傳感器網(wǎng)絡(luò)射頻信號(hào)損耗研究[J];中國(guó)農(nóng)機(jī)化學(xué)報(bào);2014年05期

6 宮繼兵;王睿;崔莉;;體域網(wǎng)BSN的研究進(jìn)展及面臨的挑戰(zhàn)[J];計(jì)算機(jī)研究與發(fā)展;2010年05期

7 劉卉;汪懋華;孟志軍;張漫;李海霞;;農(nóng)田環(huán)境中短程無(wú)線電傳播性能試驗(yàn)[J];江蘇大學(xué)學(xué)報(bào)(自然科學(xué)版);2010年01期

8 張利瓊;;無(wú)線傳感網(wǎng)絡(luò)在農(nóng)業(yè)生產(chǎn)中的應(yīng)用[J];現(xiàn)代農(nóng)業(yè)科學(xué);2008年03期

9 蔡義華;劉剛;李莉;劉卉;;基于無(wú)線傳感器網(wǎng)絡(luò)的農(nóng)田信息采集節(jié)點(diǎn)設(shè)計(jì)與試驗(yàn)[J];農(nóng)業(yè)工程學(xué)報(bào);2009年04期

10 李Pr鈺;高紅菊;姜建釗;;小麥田中天線高度對(duì)2.4GHz無(wú)線信道傳播特性的影響[J];農(nóng)業(yè)工程學(xué)報(bào);2009年S2期

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