本文選題：擴(kuò)譜通信　切入點(diǎn)：窄帶干擾抑制　出處：《國(guó)防科學(xué)技術(shù)大學(xué)》2014年碩士論文

【摘要】：擴(kuò)譜通信是目前廣泛運(yùn)用的一種抗干擾通信體制,為了提高系統(tǒng)抗干擾能力,往往在接收端進(jìn)行窄帶干擾抑制處理。論文研究了頻域窄帶抑制基本原理和基于前向連續(xù)均值去除(FCME)雙門限干擾抑制算法,針對(duì)FCME算法迭代耗時(shí)、不能適用寬信噪比范圍等缺陷,提出了一種改進(jìn)的自適應(yīng)頻域三門限干擾抑制算法,仿真表明改進(jìn)算法能夠適應(yīng)更大信噪比范圍。最后利用FPGA實(shí)現(xiàn)了改進(jìn)算法,并在實(shí)際工程中得到應(yīng)用。論文以重疊加窗FFT干擾抑制算法為基本方法,首先闡述了加窗選擇、FFT、IFFT、干擾檢測(cè)、干擾抑制等子模塊原理。針對(duì)干擾檢測(cè)方法,論文研究了單門限算法、雙門限算法和FCME算法,編程仿真了FCME干擾抑制算法性能,分析發(fā)現(xiàn)該算法在大信噪比時(shí),導(dǎo)致信號(hào)嚴(yán)重?fù)p失,無(wú)法適應(yīng)接收信號(hào)信噪比大動(dòng)態(tài)范圍情況。為了解決上述問(wèn)題,論文提出了三門限自適應(yīng)窄帶干擾抑制算法,算法基于系統(tǒng)干擾容限、干信帶寬比等先驗(yàn)參數(shù),設(shè)計(jì)了高、中、低三個(gè)門限實(shí)現(xiàn)干擾檢測(cè)與抑制,仿真表明算法能夠自適應(yīng)處理強(qiáng)弱信噪比輸入。最后利用FPGA實(shí)現(xiàn)了自適應(yīng)三門限干擾抑制算法,并仿真分析了算法實(shí)際性能與資源消耗。
[Abstract]:Spread spectrum communication is a widely used anti-interference communication system. In order to improve the anti-jamming ability of the system, narrowband interference suppression is often carried out at the receiving end.In this paper, the basic principle of narrow-band suppression in frequency domain and the dual-threshold interference suppression algorithm based on forward continuous mean method are studied. Due to the time-consuming iteration of FCME algorithm, it can not be used in wide signal-to-noise ratio (SNR) range.An improved adaptive three-threshold interference suppression algorithm in frequency domain is proposed. The simulation results show that the improved algorithm can adapt to a larger SNR range.Finally, the improved algorithm is realized by using FPGA, and it is applied in practical engineering.In this paper, the basic method of overlapped windowed FFT interference suppression algorithm is introduced. Firstly, the principle of windowed selected FFT IFFTFT module, interference detection and interference suppression module is described.In this paper, single threshold algorithm, double threshold algorithm and FCME algorithm are studied, and the performance of FCME interference suppression algorithm is simulated. It is found that the algorithm leads to serious loss of signal when the signal to noise ratio is large.It can not adapt to the large dynamic range of SNR of received signal.In order to solve the above problems, a three-threshold adaptive narrowband interference suppression algorithm is proposed. Based on the prior parameters such as system interference tolerance and ratio of signal to bandwidth, three thresholds are designed to detect and suppress interference, such as high, medium and low thresholds.Simulation results show that the algorithm can deal with strong and weak SNR input adaptively.Finally, the adaptive three-threshold interference suppression algorithm is implemented by using FPGA, and the actual performance and resource consumption of the algorithm are simulated and analyzed.
【學(xué)位授予單位】：國(guó)防科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN914.42
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本文編號(hào)：1714697