基于OFDM技术的雷达通信共享信号设计研究

发布时间：2018-04-02 01:21

本文选题：雷达通信一体化　切入点：信号能量共享　出处：《电子科技大学》2014年硕士论文

【摘要】：现今武器平台受到的威胁日趋增多,所面临的电磁环境亦更为复杂。为应对这一状况,武器平台必须装备愈来愈多的电子设备,这无疑会影响其机动性,带来电磁兼容问题,进而降低整体作战效能。为减小武器平台的体积和电磁干扰,一种有效的途径就是实现电子装备的一体化。雷达与通信作为武器平台中的两个重要组成部分,二者一体化的实现意义重大。为最大限度的实现雷达通信一体化,人们提出了信号能量共享的概念。基于信号能量共享的雷达通信一体化系统,就是利用系统公共资源,使得所设计的共享信号在实现雷达目标探测的同时,能够进行数据的高效传输。本文基于信号能量共享的思想,利用OFDM(Orthogonal Frequency Division Multiplexing,正交频分复用)技术,对雷达通信一体化信号共享做了大量的研究,主要工作和创新如下:1)分析了传统雷达系统与通信系统之间的差异性和相似性,以及雷达通信一体化实现所带来的资源约束问题。在此基础上,建立了对雷达通信共享信号进行评价和设计的基本准则。2)在分析现有的基于OFDM和基于伪随机序列的雷达通信一体化实现方式缺陷的基础上,通过将OFDM技术与扩频技术相结合设计了一种新的共享信号,即MC-CDMA(Multicarrier CDMA,多载波码分多址)共享信号。扩频技术的使用,使得该共享信号具有更低的截获概率、更强的通信保密性以及潜在的多址能力,同时较现有OFDM共享信号的峰均功率比低4d B以上。3)对MC-CDMA共享信号和LFM信号模糊函数进行了对比分析,前者具有图钉形的模糊函数,但距离和多普勒旁瓣较高。针对这一问题,本文就MC-CDMA信号特殊的时频域结构,引入了一种基于调制符号的雷达信号处理算法,并利用加窗旁瓣抑制技术对其进行了改进,加窗加权使得MC-CDMA信号距离旁瓣最大可降低47d B。此外,该算法可以彻底消除共享信号中所调信息对目标检测的影响,较传统的基于相关的处理方法,距离旁瓣最大可降低45 d B。4)针对OFDM信号峰均功率比较大以及CE-OFDM(Constant Envelope OFDM,恒包络OFDM)信号载波间干扰有待降低的缺陷,结合恒包络调制技术以及MSK信号快速滚降的频谱特性设计了一种新的共享信号,即CE-MSK-OFDM共享信号。该信号使得OFDM信号峰均功率比降至0d B这一理想状态,并有效降低CE-OFDM信号的载波间干扰。5)将CE-MSK-OFDM共享信号与理想相位编码下的OFDM雷达信号模糊函数进行了对比。仿真表明,CE-MSK-OFDM共享信号具有更好的模糊函数特性,所携带的通信信息几乎不会对系统雷达性能带来负面的影响。为便于后续系统波形参数的设计,还对各个参数对其模糊函数性能的影响进行了仿真分析。6)从系统的角度出发,对系统波形参数、工作模式以及链路维护进行了设计与分析,并分别构建了基于MC-CDMA和CE-MSK-OFDM的雷达通信一体化系统框架,对系统的雷达性能和通信性能进行了仿真分析。仿真表明,链路连通区内平均吞吐率在2 Mbps以上,在良好的波束控制下,可以达到更高。可见,本文所设计的两种雷达通信共享信号,是可以满足战场应用要求的。
[Abstract]:The weapon platform threat is increasing, the electromagnetic environment is more complicated. In response to this situation, the weapon platform must be electronic equipment more and more, which will undoubtedly affect the mobility, bring electromagnetic compatibility problems, thereby reducing the overall operational efficiency. As to reduce the volume of the weapon platform and electromagnetic interference, a which is the effective way to realize the integration of electronic equipment. The radar and communication as the two important part of weapon platform, the integration of the two to achieve significant. For the realization of radar communication integration to the maximum, people put forward the concept of signal sharing. Radar communication integration system based on signal energy sharing, is the use of the system of public resources, the design of the shared signal in the realization of radar target detection at the same time, it can efficiently transfer data. Based on the signal The amount of sharing ideas, using OFDM (Orthogonal Frequency Division Multiplexing, orthogonal frequency division multiplexing) technology of radar communication integration signal sharing has done a lot of research, the main work and innovation are as follows: 1) analyze the differences between the traditional radar system and communication system and similarity, and radar communication integration to realize the resource constraint problem brings. On this basis, the establishment of evaluation and design of the basic principles of.2 radar communication sharing signal) based on analyzing current OFDM and pseudo random sequence based on a radar communication way based on the defects, the OFDM technology and spread spectrum technology combined with the design of a new shared the signal, namely MC-CDMA (Multicarrier CDMA, multi carrier CDMA) sharing signal. Use spread spectrum technology, which makes the sharing signal has lower intercept probability, stronger communication Confidentiality and potential multiple access capability, at the same time compared with the existing OFDM 4D B low share signal peak to average power ratio of more than.3) fuzzy function analyses MC-CDMA share and LFM signals, the former has a thumbtack ambiguity function, but the distance and Doppler high sidelobe. To solve this problem, the time and frequency domain the special structure of MC-CDMA signal, we introduce a method of radar signal processing based on modulation symbols, and it was improved by using window sidelobe suppression technology, windowed MC-CDMA signal has the maximum weighted distance sidelobe can be reduced by 47D B. in addition, the algorithm can eliminate the influence of information sharing on the target detection signal. Processing method based on correlation over the maximum distance sidelobe can be reduced by 45 D B.4) for OFDM signal peak to average power ratio and CE-OFDM (Constant Envelope OFDM OFDM, the constant envelope signal carrier) To reduce the interference between the defect, a new shared signal design with spectrum characteristics of constant envelope modulation technology and MSK signal fast rolloff, namely CE-MSK-OFDM signal. The signal sharing makes OFDM signal peak to average power ratio of B to 0d this ideal state, and effectively reduce the CE-OFDM signal carrier interference.5) will CE-MSK-OFDM shared OFDM radar signal and the ideal signal phase encoding between the ambiguity function. Simulation results show that CE-MSK-OFDM has better signal ambiguity function sharing, negative impact on communication information carried by the radar system does little to facilitate subsequent performance. For the design of system parameters, the influence of various parameters on the fuzzy function is simulated.6) from the perspective of the system, the system of waveform parameters, working mode and link maintenance for the design and analysis, and Respectively constructs the framework of radar communication integration system of MC-CDMA and CE-MSK-OFDM based on radar performance and the performance of communication system is simulated. Simulation results show that the average throughput of link connectivity rate in the region more than 2 Mbps, in good beam control, can achieve higher. Therefore, the design of the two kinds of radar communication share the signal, it can meet the application requirements of the battlefield.

【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.51

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