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OFDM擴(kuò)頻技術(shù)在水聲通信中的應(yīng)用研究

發(fā)布時(shí)間:2018-06-07 20:25

  本文選題:水聲通信 + 正交頻分復(fù)用 ; 參考:《哈爾濱工程大學(xué)》2014年碩士論文


【摘要】:伴隨著海洋事業(yè)的壯大,水下通信業(yè)務(wù)繁忙,發(fā)展網(wǎng)絡(luò)化水聲通信刻不容緩。其中,水下網(wǎng)絡(luò)多用戶通信已逐漸成為水聲通信研究的熱點(diǎn)。擴(kuò)頻(Spread-Spectrum,SS)技術(shù)作為一種抗干擾和抗衰落能力強(qiáng)的通信技術(shù),發(fā)射功率低、可靠性高、保密性好,具有廣泛的應(yīng)用。正交頻分復(fù)用(Orthogonal Frequency Division Multiplexing, OFDM)技術(shù)是一種抗頻率選擇性衰落能力強(qiáng)、頻譜利用率高、傳輸速率高的通信技術(shù),將其與擴(kuò)頻技術(shù)相結(jié)合應(yīng)用于水下通信,能大大增加系統(tǒng)的抗干擾和抗衰落能力,對(duì)于水下多用戶通信的發(fā)展具有深遠(yuǎn)意義。本文主要研究OFDM擴(kuò)頻技術(shù)在水聲通信中的應(yīng)用。論文最初對(duì)擴(kuò)頻技術(shù)、OFDM技術(shù)的基本原理進(jìn)行了理論分析,并研究了擴(kuò)頻與OFDM結(jié)合的三種方式,分析了頻域擴(kuò)頻MC-CDMA、正交MCDS-CDMA和多音DS-CDMA的實(shí)現(xiàn)過(guò)程,通過(guò)仿真驗(yàn)證了頻域擴(kuò)頻的優(yōu)越性,該擴(kuò)頻方式充分利用了頻率分集增益,抗多徑衰落能力更好。擴(kuò)頻通信技術(shù)抗多徑干擾能力強(qiáng),適用于較低信噪比條件,并且具有很好地組網(wǎng)能力。本文在實(shí)現(xiàn)直接序列擴(kuò)頻與OFDM結(jié)合的基礎(chǔ)上,研究了循環(huán)移位擴(kuò)頻OFDM技術(shù)和組合擴(kuò)頻OFDM技術(shù),這兩種技術(shù)擁有更高的通信速率。仿真驗(yàn)證了無(wú)循環(huán)前綴的OFDM擴(kuò)頻系統(tǒng)仍可以保持高效可靠的解碼。在水聲通信中,空間的變化對(duì)水聲信道沖激響應(yīng)函數(shù)影響甚大,這使得不同空間位置上的水聲信道的沖激響應(yīng)函數(shù)具備弱相關(guān)性。利用水聲信道的這一物理特性,將時(shí)間反轉(zhuǎn)鏡技術(shù)用于多用戶水聲通信中,以聚焦期望用戶,屏蔽非期望用戶實(shí)現(xiàn)空分多址。本文構(gòu)建基于時(shí)間反轉(zhuǎn)鏡技術(shù)的OFDM擴(kuò)頻多用戶水聲通信系統(tǒng),實(shí)現(xiàn)了多個(gè)用戶的可靠通信。然后提出差分OFDM擴(kuò)頻技術(shù),差分技術(shù)在接收端采用差分相干解調(diào)的方法,削弱水聲衰落信道引起的性能下降問(wèn)題,不需要相干解調(diào)和信道估計(jì),提高系統(tǒng)的頻帶利用率,降低系統(tǒng)的復(fù)雜度和計(jì)算量,將其結(jié)合OFDM擴(kuò)頻技術(shù)應(yīng)用于多用水聲通信中,能建立穩(wěn)健的通信系統(tǒng)。本文對(duì)所研究的算法進(jìn)行了計(jì)算機(jī)仿真實(shí)驗(yàn)和水池試驗(yàn)驗(yàn)證,結(jié)果表明:擴(kuò)頻技術(shù)與OFDM技術(shù)相結(jié)合提高了水聲通信系統(tǒng)的性能,實(shí)現(xiàn)了高質(zhì)量點(diǎn)對(duì)點(diǎn)水聲通信和多用戶水聲通信。
[Abstract]:With the development of ocean business, underwater communication business is busy, so it is urgent to develop network underwater acoustic communication. Among them, underwater network multi-user communication has gradually become the hot spot of underwater acoustic communication research. As a kind of communication technology with strong anti-interference and anti-fading ability, spread spectrum SS (spread Spectrum) technology has a wide range of applications, such as low transmission power, high reliability and good confidentiality. Orthogonal Frequency Division Multiplexing (OFDM) is a kind of communication technology with strong anti-frequency selective fading ability, high spectral efficiency and high transmission rate. It can greatly increase the anti-interference and anti-fading ability of the system, and has far-reaching significance for the development of underwater multi-user communication. This paper mainly studies the application of OFDM spread spectrum technology in underwater acoustic communication. At the beginning of this paper, the basic principle of spread spectrum technology and OFDM technology is theoretically analyzed, and three ways of combining spread spectrum with OFDM are studied, and the realization process of spread spectrum MC-CDMA, orthogonal MCDS-CDMA and multi-tone DS-CDMA in frequency domain is analyzed. The superiority of spread spectrum in frequency domain is verified by simulation. The spread spectrum method makes full use of frequency diversity gain and has better anti-multipath fading ability. Spread spectrum communication technology has strong ability to resist multipath interference, is suitable for low signal-to-noise ratio (SNR), and has good networking ability. Based on the combination of direct sequence spread spectrum (DSSS) and OFDM, the cyclic shift spread spectrum OFDM technology and the combined spread spectrum OFDM technology are studied in this paper. These two technologies have higher communication rate. Simulation results show that OFDM spread spectrum system without cyclic prefix can still be decoded efficiently and reliably. In underwater acoustic communication, spatial variation has a great influence on the impulse response function of underwater acoustic channel, which makes the impulse response function of underwater acoustic channel have weak correlation. Based on this physical property of underwater acoustic channel, the time reversal mirror technique is used in multi-user underwater acoustic communication to focus on the desired users and shield the non-expected users to realize space-division multiple access (SDMA). In this paper, the OFDM spread spectrum multi-user underwater acoustic communication system based on time reversal mirror is constructed, and the reliable communication of multiple users is realized. Then the differential OFDM spread spectrum technique is proposed, which adopts differential coherent demodulation at the receiver to weaken the performance degradation problem caused by underwater acoustic fading channel, without the need of coherent demodulation and channel estimation, so as to improve the frequency band efficiency of the system. In order to reduce the complexity and computational complexity of the system, a robust communication system can be established by applying OFDM spread spectrum technology to multi-purpose underwater acoustic communication. In this paper, computer simulation experiments and tank experiments are carried out to verify the proposed algorithm. The results show that the performance of underwater acoustic communication system is improved by the combination of spread spectrum technology and OFDM technology. High-quality point-to-point underwater acoustic communication and multi-user underwater acoustic communication are realized.
【學(xué)位授予單位】:哈爾濱工程大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2014
【分類號(hào)】:TN929.3;TN929.53

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 殷敬偉;王馳;潘爭(zhēng)榮;張鈺珩;;基于MDAPSK的OFDM水聲通信研究[J];華中科技大學(xué)學(xué)報(bào)(自然科學(xué)版);2013年03期

2 胡茂凱;陳西宏;張群;;多徑衰落信道下MC-DS-CDMA系統(tǒng)性能分析[J];華中科技大學(xué)學(xué)報(bào)(自然科學(xué)版);2013年01期

3 陳陽(yáng);張藝朦;陳凱;趙安邦;;基于同步導(dǎo)頻復(fù)用技術(shù)的OFDM水聲通信[J];華中科技大學(xué)學(xué)報(bào)(自然科學(xué)版);2011年08期

4 程恩;袁飛;蘇為;高春仙;曾文俊;孫海信;胡曉毅;;水聲通信技術(shù)研究進(jìn)展[J];廈門大學(xué)學(xué)報(bào)(自然科學(xué)版);2011年02期

5 殷敬偉;張曉;趙安邦;生雪莉;;時(shí)間反轉(zhuǎn)鏡在水聲通信網(wǎng)上行通信中的應(yīng)用[J];哈爾濱工程大學(xué)學(xué)報(bào);2011年01期

6 孔繁慧;張學(xué)森;馮海泓;;MC-CDMA技術(shù)在水聲通信中的應(yīng)用研究[J];聲學(xué)技術(shù);2010年04期

7 何成兵;黃建國(guó);韓晶;張群飛;;循環(huán)移位擴(kuò)頻水聲通信[J];物理學(xué)報(bào);2009年12期

8 戴榮濤;王青春;;現(xiàn)代水聲通信技術(shù)的發(fā)展及應(yīng)用[J];科技廣場(chǎng);2008年08期

9 何成兵;黃建國(guó);閻振華;蘇剭;;M元擴(kuò)頻OFDM水聲通信新方法[J];西北工業(yè)大學(xué)學(xué)報(bào);2007年02期

10 黃曉萍;桑恩方;;一個(gè)水聲擴(kuò)頻通信系統(tǒng)設(shè)計(jì)與實(shí)現(xiàn)[J];海洋工程;2007年01期

相關(guān)會(huì)議論文 前1條

1 黃建國(guó);孫靜;何成兵;申曉紅;雷開(kāi)卓;;OFDM高速水聲通信系統(tǒng)及實(shí)驗(yàn)研究[A];通信理論與信號(hào)處理新進(jìn)展——2005年通信理論與信號(hào)處理年會(huì)論文集[C];2005年

相關(guān)博士學(xué)位論文 前4條

1 周鋒;水聲擴(kuò)頻通信關(guān)鍵技術(shù)研究[D];哈爾濱工程大學(xué);2012年

2 徐小卡;基于OFDM的淺海高速水聲通信關(guān)鍵技術(shù)研究[D];哈爾濱工程大學(xué);2009年

3 殷敬偉;多途信道中Pattern時(shí)延差編碼水聲通信研究[D];哈爾濱工程大學(xué);2007年

4 王明華;高速水聲通信中OFDM的關(guān)鍵技術(shù)與應(yīng)用研究[D];哈爾濱工程大學(xué);2007年

相關(guān)碩士學(xué)位論文 前6條

1 侯娟;混沌偽隨機(jī)序列的產(chǎn)生及其在擴(kuò)頻通信系統(tǒng)中的應(yīng)用[D];華南理工大學(xué);2012年

2 盧小莉;基于OFDM擴(kuò)頻通信技術(shù)的算法研究與實(shí)現(xiàn)[D];電子科技大學(xué);2012年

3 孫立強(qiáng);時(shí)反鏡擴(kuò)頻水聲通信技術(shù)研究[D];哈爾濱工程大學(xué);2011年

4 魏波;基于OFDM的擴(kuò)頻通信技術(shù)研究[D];電子科技大學(xué);2010年

5 解愷;基于多載波直擴(kuò)碼分多址的水聲通信技術(shù)研究與實(shí)現(xiàn)[D];哈爾濱工程大學(xué);2010年

6 顏杰敏;水聲通信網(wǎng)中的MC-CDMA技術(shù)研究[D];廈門大學(xué);2008年

,

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