【摘要】：認知雷達不僅具有接收自適應能力,而且通過接收端到發(fā)射端的反饋可以獲得發(fā)射端的自適應能力,因此,認知雷達是一個閉環(huán)的自適應系統(tǒng)。MIMO雷達具有比相控陣雷達更高的發(fā)射自由度,將MIMO雷達與認知雷達結(jié)合的認知MIMO雷達是廣受學者關注的新體制雷達。本文將認知MIMO雷達運用到機載平臺,結(jié)合理論推導和建模仿真,研究了機載平臺下色噪聲及雜波的抑制問題,主要工作內(nèi)容如下:1、介紹了機載認知MIMO雷達的基本系統(tǒng)框架以及可行布陣方式,說明了認知信息獲取及空時優(yōu)化設計的基本方法,詳細介紹了機載平臺下的雜波建模和信息提取方法。2、研究了機載認知MIMO雷達的波形設計問題,以最大化SNR為準則,分析了多種基于特征值的波形設計方法,并重點研究了色噪聲情況下的恒模波形設計方法,該方法以基于特征值方法優(yōu)化的波形為目標波形,采用序貫二次規(guī)劃進行MIMO波形編碼,該方法充分利用了發(fā)射陣元的自由度及發(fā)射功率,進一步提高了輸出SNR。3、研究了機載認知MIMO雷達的發(fā)射空時權(quán)設計問題。分別對相控陣模式及MIMO模式下的發(fā)射空時權(quán)優(yōu)化方法進行了介紹和仿真,相控陣模式下的空時權(quán)優(yōu)化采用MVDR方法,可以在發(fā)射空時方向圖上形成對應雜波脊的凹槽;MIMO模式下的空時權(quán)優(yōu)化通過引入轉(zhuǎn)移矩陣,以最大化SCNR為準則,進行問題建模和優(yōu)化求解,可以有效抑制雜波,同時可以降低對接收機動態(tài)范圍的要求,簡化接收端信號處理的結(jié)構(gòu)。4、針對復雜電磁環(huán)境,研究了機載認知MIMO雷達的空時頻三維優(yōu)化問題。針對雜波和平穩(wěn)色噪聲背景,采用分步優(yōu)化,即時域波形優(yōu)化抑制色噪聲的影響,空頻域優(yōu)化抑制雜波;針對雜波和非平穩(wěn)色噪聲環(huán)境,采用空時頻三維聯(lián)合優(yōu)化,同時抑制雜波、干擾和色噪聲的影響。
[Abstract]:Cognitive radar not only has adaptive ability to receive, but also can obtain adaptive capability of transmitter through feedback from receiver to transmitter. Cognitive radar is a closed-loop adaptive system. MIMO radar has higher degree of freedom than phased array radar. The cognitive MIMO radar which combines MIMO radar and cognitive radar is a new system radar which is widely concerned by scholars. In this paper, the cognitive MIMO radar is applied to the airborne platform. Combining with theoretical derivation and modeling and simulation, the suppression of color noise and clutter under the airborne platform is studied. The main work is as follows: 1. The basic system framework and feasible array method of airborne cognitive MIMO radar are introduced, and the basic methods of cognitive information acquisition and space-time optimization design are explained. The methods of clutter modeling and information extraction under airborne platform are introduced in detail. 2. The waveform design of airborne cognitive MIMO radar is studied. Taking maximization SNR as the criterion, several waveform design methods based on eigenvalue are analyzed. The design method of constant modulus waveform in the case of color noise is studied. The waveform optimized based on eigenvalue method is taken as the target waveform, and the sequential quadratic programming is used to code the MIMO waveform. This method makes full use of the degree of freedom and the transmitting power of the emitter elements, and further improves the output SNR.3, to study the design of space-time weight of airborne cognitive MIMO radar. The methods of space-time weight optimization in phased array mode and MIMO mode are introduced and simulated respectively. The MVDR method is used to optimize space-time weight in phased array mode. The grooves corresponding to clutter ridges can be formed on the transmitted space-time pattern, and the optimization of space-time weights in MIMO mode can effectively suppress clutter by introducing transfer matrix and using maximization SCNR as the criterion to model and solve the problem. At the same time, it can reduce the requirement of receiver dynamic range and simplify the structure of receiver signal processing. 4. For complex electromagnetic environment, the space-time-frequency optimization problem of airborne cognitive MIMO radar is studied. For clutter and stationary color noise background, step by step optimization and real-time waveform optimization are used to suppress the influence of color noise, space-frequency domain optimization is used to suppress clutter, and for clutter and non-stationary color noise environment, three dimensional space-time-frequency joint optimization is adopted. At the same time, the effects of clutter, interference and color noise are suppressed.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：V243.2

【參考文獻】

相關期刊論文 前2條

1 黎湘;范梅梅;;認知雷達及其關鍵技術(shù)研究進展[J];電子學報;2012年09期

2 王宏強;夏洪恩;程永強;王璐璐;;基于MPDA的波形自適應目標跟蹤[J];系統(tǒng)工程與電子技術(shù);2011年11期

相關博士學位論文 前1條

1 孫穎;MIMO與認知雷達波形設計理論與算法研究[D];電子科技大學;2014年

，

本文編號：2266093