【摘要】：近年來(lái),隨著軍事思想和通信體制的不斷發(fā)展與變革,通信干擾的作用顯得越來(lái)越重要。多輸入多輸出(MIMO)系統(tǒng)由于具有高頻譜利用率、大容量等特點(diǎn),已被廣泛地應(yīng)用于軍事和民用領(lǐng)域。針對(duì)MIMO系統(tǒng)的干擾,傳統(tǒng)干擾手段大多是基于在目標(biāo)信號(hào)所在的載頻范圍內(nèi)添加噪聲等方式,雖仍然有效,但其固有的干擾功率大、不利于隱蔽、無(wú)法持續(xù)干擾等缺點(diǎn)限制了其應(yīng)用場(chǎng)景和范圍。而且,隨著近年來(lái)抗干擾技術(shù)的不斷發(fā)展,也給干擾帶來(lái)了極大的挑戰(zhàn)。靈巧式干擾是通過(guò)采用較低的干擾功率在隱蔽自身的前提下,針對(duì)某一通信系統(tǒng)的特點(diǎn)設(shè)法擾亂其數(shù)字信號(hào)傳輸?shù)哪骋魂P(guān)鍵環(huán)節(jié)。因此,針對(duì)MIMO系統(tǒng)的靈巧式干擾就具有巨大的應(yīng)用前景。本文主要圍繞MIMO系統(tǒng)靈巧式干擾開展了一系列探索性研究。首先,對(duì)MIMO系統(tǒng)的特點(diǎn)進(jìn)行了分析,并介紹了常用的同步以及信道估計(jì)算法,為后續(xù)分析靈巧式干擾對(duì)同步以及信道估計(jì)的影響奠定了基礎(chǔ)。然后,分析了基于導(dǎo)頻置零的信道估計(jì)干擾策略以及訓(xùn)練序列置零的同步干擾策略。為了進(jìn)一步減少上述干擾策略對(duì)于信道等先驗(yàn)信息的要求,提出一種性能折中的改進(jìn)型信道估計(jì)干擾策略。該策略首先需要偵聽機(jī)識(shí)別出目標(biāo)信號(hào)的導(dǎo)頻,通過(guò)對(duì)導(dǎo)頻重構(gòu)并發(fā)送以達(dá)到導(dǎo)頻污染的目的,進(jìn)而導(dǎo)致合作接收機(jī)的信道估計(jì)出現(xiàn)錯(cuò)誤。仿真結(jié)果表明,該策略在低干信比條件下具有良好的干擾效果。為了克服干擾信號(hào)與目標(biāo)信號(hào)之間相對(duì)時(shí)延差對(duì)干擾效果的影響,提出一種同步欺騙式干擾策略。該策略通過(guò)在合作接收端的同步過(guò)程中構(gòu)造虛假相關(guān)峰值,從而達(dá)到欺騙同步的目的。仿真結(jié)果表明,該策略能利用相對(duì)時(shí)延差這一不利因素,在干信比為0dB以上時(shí)具有較好的干擾效果。最后,為了給干擾機(jī)在天線數(shù)目的選擇上提供參考,提出了一種基于改進(jìn)型蓋爾圓的天線數(shù)目盲估計(jì)算法,保證了在低信噪比條件下良好的估計(jì)性能。出于降低在干擾信號(hào)構(gòu)造過(guò)程中對(duì)幀參等先驗(yàn)信息要求的目的,探討了一種基于二階統(tǒng)計(jì)量的干擾信號(hào)構(gòu)造策略。該策略首先構(gòu)造干擾信號(hào)的二階統(tǒng)計(jì)量,進(jìn)而根據(jù)二階統(tǒng)計(jì)量進(jìn)行干擾信號(hào)的構(gòu)造。從而可以實(shí)現(xiàn)以較低的干擾功率實(shí)施有效的干擾。仿真結(jié)果表明,該策略可以在進(jìn)一步降低干擾信號(hào)對(duì)幀參等先驗(yàn)信息要求的基礎(chǔ)上獲得較好的干擾效果。
[Abstract]:In recent years, with the development and reform of military thought and communication system, communication interference is becoming more and more important. Multi-input multiple-output (MIMO) systems have been widely used in military and civilian fields due to their high spectral efficiency and large capacity. For the interference of MIMO system, most of the traditional jamming methods are based on adding noise in the carrier frequency range of the target signal. Although it is still effective, its inherent interference power is large, which is not conducive to concealment. Its application scenarios and scope are limited by its disadvantages such as unsustainable interference and so on. Moreover, with the continuous development of anti-jamming technology in recent years, it also brings great challenges to interference. Dexterous interference is a key part of digital signal transmission which is disturbed by using low interference power and hiding itself according to the characteristics of a communication system. Therefore, the dexterous interference for MIMO system has a great application prospect. In this paper, a series of exploratory researches are carried out around the dexterous interference of MIMO system. Firstly, the characteristics of MIMO system are analyzed, and the commonly used synchronization and channel estimation algorithms are introduced, which lays a foundation for the subsequent analysis of the influence of dexterous interference on synchronization and channel estimation. Then, the channel estimation interference strategy based on pilot zero and the synchronization jamming strategy of training sequence zeroing are analyzed. In order to further reduce the need for prior information such as channel, a performance compromise improved channel estimation interference strategy is proposed. The strategy first requires the listener to identify the pilot of the target signal. By reconstructing the pilot frequency and transmitting it to achieve the purpose of pilot pollution, the channel estimation error of the cooperative receiver will occur. The simulation results show that the strategy has good interference effect under the condition of low signal-to-interference ratio. In order to overcome the influence of the relative delay difference between the jamming signal and the target signal on the jamming effect, a synchronous deception jamming strategy is proposed. The strategy constructs false correlation peaks in the synchronization process of the cooperative receiver, so as to achieve the purpose of spoofing synchronization. The simulation results show that the strategy can take advantage of the unfavorable factor of relative delay difference and has a better jamming effect when the ratio of signal to interference is above 0dB. Finally, in order to provide a reference for the selection of the number of antennas of the jammer, an improved algorithm for blind estimation of antenna numbers based on the improved Gaelic circle is proposed, which ensures a good estimation performance under the condition of low signal-to-noise ratio (SNR). In order to reduce the requirement of a priori information such as frame parameters in the construction of interference signals, a strategy of constructing interference signals based on second-order statistics is discussed. Firstly, the second order statistics of the interference signal are constructed, and then the second order statistics are used to construct the interference signal. Thus, the effective interference can be implemented with lower interference power. Simulation results show that the proposed strategy can achieve better interference effect on the basis of further reducing the requirement of prior information such as frame parameters.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TN919.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前6條

1 蒯偉;張志輝;;最佳遮蓋性干擾的應(yīng)用研究[J];信息技術(shù)與信息化;2012年03期

2 郭富強(qiáng);于雨;王呈貴;白傳芳;;基于OFDM同步系統(tǒng)的靈巧干擾方法研究[J];通信對(duì)抗;2008年01期

3 朱慶厚;;通信同步的干擾(Ⅱ)[J];航天電子對(duì)抗;2005年06期

4 Bakir Mohammed,李外云,Belhachat Messaouda,劉錦高,朱守正;衰落性AWGN信道的OFDM性能保護(hù)間隔的優(yōu)化(英文)[J];華東師范大學(xué)學(xué)報(bào)(自然科學(xué)版);2005年03期

5 殷杰;寬帶無(wú)線電通信干擾的設(shè)想[J];計(jì)算機(jī)與網(wǎng)絡(luò);2005年11期

6 易大方;移動(dòng)通信對(duì)抗中的遮蓋性干擾技術(shù)[J];電訊技術(shù);2003年03期

，

本文編號(hào)：2356939