本文選題：單通道 + 抗干擾��； 參考：《電子科技大學》2014年碩士論文

【摘要】：早期的擴頻通信技術由于其更為理想的抗干擾能力主要應用在軍事通信領域。由于民用通信需求的日益增長和頻譜資源的日益稀缺,擴頻通信在數(shù)字移動蜂窩通信領域也得到了廣泛應用。本文針對擴頻通信模型提出一種基于單通道盲分離技術的信號偵察和測量方法,并在實際環(huán)境檢驗了該方法的可行性。本文首先介紹了經典的盲分離算法,包括Comon算法、特征矩陣近似聯(lián)合對角化(JADE)算法、不動點ICA算法(Fast-ICA),它們是單通道盲分離的理論基礎。其次介紹了IS-95標準下擴頻通信的信道模型,這一模型的特點決定了可以將基于ICA-R的單通道盲分離技術應用在其之上。文章的最后一部分給出了實際通信環(huán)境下的測量結果,證實了算法在抽取期望信號上的有效性以及在不同信干比(SIR)的信道環(huán)境下的抗干擾能力。由于單通道技術可以突破傳統(tǒng)的多天線瓶頸,大大簡化設備的復雜程度,因而在未來信號測量領域尤其是戰(zhàn)術通信領域有重要實用價值。本文利用了直擴信號的特點及其在信號偵察情況下的的特殊環(huán)境。干擾信號和白噪聲通常情況下和直擴信號在頻域嚴重重疊,而傳統(tǒng)的時頻域信號處理方法很難對同頻信號進行有效分離,波束成形方法也存在很多不足之處。本文提出的基于ICA-R的單通道盲信號抽取算法,可以在已知導引序列的條件下有效的分離出目的信號,顯著提升信號偵察的準確程度。限于實驗條件,本文利用波形貼近度和Walsh譯碼峰均比來考察分離效果。波形貼近度和Walsh譯碼峰均比表征了對待偵察的信號的估計的可靠性。仿真和實測結果表明,我們的算法得到的波形比直接采樣得到的波形在貼近度上有較大改善,在信道環(huán)境較差,即低信噪比的情況下有0.1-0.2的提升。在峰均比上,也有2dB左右的性能提升�？偟膩碚f,我們可以僅利用一根接收天線即可實現(xiàn)提高信號偵察的可靠性。
[Abstract]:The early spread spectrum communication technology was mainly used in military communication field because of its better anti-jamming capability. Due to the increasing demand for civil communications and the increasing scarcity of spectrum resources, spread spectrum communication has been widely used in the field of digital mobile cellular communications. In this paper, a signal reconnaissance and measurement method based on single channel blind separation is proposed for spread spectrum communication model. The feasibility of this method is verified in practical environment. In this paper, we first introduce classical blind separation algorithms, including Comon algorithm, eigenmatrix approximation combined with diagonalization (JADE) algorithm, fixed point ICA algorithm (Fast-ICA), which are the theoretical basis of single-channel blind separation. Secondly, the channel model of spread spectrum communication based on IS-95 standard is introduced. The characteristics of this model determine that the ICA-R based single-channel blind separation technology can be applied to it. In the last part of the paper, the measurement results under the actual communication environment are given, and the validity of the algorithm in extracting desired signals and the anti-jamming ability in the channel environment with different signal-to-interference ratio (SIRs) are verified. Single channel technology can break through the traditional multi-antenna bottleneck and greatly simplify the complexity of the equipment, so it has important practical value in the field of signal measurement, especially in the field of tactical communication. This paper makes use of the characteristics of DS signal and its special environment in the case of signal reconnaissance. The interference signal and white noise usually overlap with the DSSS signal in the frequency domain seriously, but the traditional time-frequency domain signal processing method is very difficult to effectively separate the same frequency signal, and the beamforming method also has many shortcomings. The single channel blind signal extraction algorithm based on ICA-R proposed in this paper can effectively separate the target signal under the condition of known guidance sequence and significantly improve the accuracy of signal reconnaissance. Under experimental conditions, the separation effect is investigated by using waveform closeness and Walsh decoding peak to average ratio. The waveform closeness and Walsh decoding peak ratio represent the reliability of the estimation of the reconnaissance signal. The simulation and experimental results show that the waveform obtained by our algorithm is much better than that obtained by direct sampling in terms of closeness, and is improved by 0.1-0.2 in the case of low signal-to-noise ratio (SNR). At the peak to average ratio, there is also about 2 dB performance improvement. In general, we can improve the reliability of signal reconnaissance by using only one receiving antenna.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN914.42;TN973

【參考文獻】

相關碩士學位論文 前1條

1 信子君;通信信號與干擾信號的半盲分離算法研究[D];電子科技大學;2013年

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本文編號：2018587