低成本扩频数字波束形成技术研究
毕业论文关键词 数字波束形成 正交码 扩频 速度补偿
Title Research of low cost spread spectrum digital beamforming
Abstract Digital technique is used in digital beamforming to adjust amplitude and phase weights of array antenna elements to form smart antenna beam pattern. Several independent and controllable beams can be formed, with flexible beam control, high signal gain, and strong anti-jamming capability. But disadvantages such as high cost, higher limits of volume, weight and power also exist in digital beamforming system. The low cost spread spectrum digital beamforming radar system proposed in " Spread Spectrum Digital Beamforming in Radar ( SSDBF )" by Dr Marcos A. Bergamo, Applied Radar Inc, is simulated in this paper. And its technical principle and implementation process is analyzed. In addition, the performance of the system is analyzed and tested, which validates the feasibility of this system. Finally, based on the coupling problem in velocity measuring and angle measuring of moving target, a velocity compensation method is proposed. The feasibility analysis of this method and the scope of application is verified.
Keywords Digital Beamforming , TSOC ， spread spectrum ,velocity compensation
目录
1 引言 1
1.1 论文的研究背景和意义 1
1.2 国内外研究动态 2
2 扩频数字波束形成基础 3
2.1 自适应阵列天线 3
2.1.1 阵列天线的基本模型 3
2.1.2 均匀线阵 4
2.1.3 均匀圆阵 6
2.1.4 平面矩形阵 7
2.2 伪随机序列 8
2.2.1 m序列的产生 . 8
2.2.2 m序列的性质 11
3. SSDBF 系统组成与原理 . 13
3.1 传统数字波束形成系统 13
3.2 SSDBF 系统的工作原理 . 14
3.3 SSDBF 的波形和码型选择 . 16
4 系统仿真与性能分析 19
4.1 仿真参数选择 20
4.2 静止多目标测距和测角性能仿真 22
4.2.1 仿真过程及结果 22
4.3 单个移动目标测速性能仿真 27
4.3.1 仿真过程及结果 28
4.3.2 仿真结果分析 37
4.3.3 改进措施 37
5 项目总结和展望 40
致谢 41
参考文献 42
1 引言 1.1 论文的研究背景和意义 雷达是现代信息化战争中最重要的信息获取装备，为了适应日益严峻的目标环境和复杂的电磁环境，雷达的性能必须有显著的提高，必须具备高精度、多种模式多目标探测、抗干扰性能、多种自适应和目标识别能力。随着直接数字频率合成技术（DDS）、模数转换技术（ADC）等数字技术及电子技术，尤其是超大规模数字电路、多元件 T/R模块、微处理芯片及光纤的发展，数字阵列雷达会逐渐替代模拟雷达，并以其无可比拟的优势成为相控阵雷达的一个重要发展方向[6]。 自适应阵列天线是通过调节阵列天线中每个阵元的加权值来改变阵列方向图的形状，使其主瓣总指向期望信号方向，并且在干扰信号方向形成零陷，以此提高天线的增益和信干噪比。