基于压缩感知的超宽带侦察信号处理研究

发布时间：2018-03-31 19:37

本文选题：压缩感知　切入点：AIC　出处：《西安电子科技大学》2015年硕士论文

【摘要】：宽带数字侦察系统在雷达对抗中担负着重要的角色,具有大瞬时带宽和多信号处理的能力,为提高其瞬时带宽需要采用高速数据采集技术,而AD芯片固有的模拟带宽限制了高速数据采集技术的发展。针对以上问题,本文提出了一种基于压缩感知理论的超宽带侦察信号处理技术,在进行数据采集的过程中打破了奈奎斯特采样定理的限制,降低了AD转换的采样率,能够在短时间内完成对全频段范围内雷达辐射源信号的获取和参数测量。论文根据雷达信号在时、空、频域具有稀疏性的特点,将压缩感知理论应用于宽带侦察信号处理中,提出了基于压缩感知的宽带数字侦察信号处理方案,采用AIC(Analog-to-Information Conversion)采样结构完成了对侦察接收信号的压缩感知数据采集,对于简单雷达信号压缩倍数可达32,其中利用Gold码可使用的伪随机序列数量较多的特点,选取其作为伪随机序列对模拟信号进行调制;提出了将参数估计算法运用于AIC结构后端的信号处理方法,直接利用观测数据进行原始信号参数估计,避免了信号重构过程,在很大程度上提升了信号参数的获取速度,能够完成的频率检测范围为:10MHz~16GHz,基本覆盖了雷达的工作频带范围;在此基础上,结合能量阈值和频率的一致性估计,研究了一种雷达脉冲信号检测方法,并且通过引入基于离散椭球序列的消零算法,消除了干扰频带的影响,实现了对交叠脉冲的检测和参数提取;最后分析了不同因素对文中所提方法进行信号参数提取的影响,主要的影响因素包括观测矩阵、信号密度及信号动态范围、信噪比和压缩倍数等,从而得到了基于压缩感知的超宽带信号处理方法的普遍适用范围。
[Abstract]:Wideband digital reconnaissance system plays an important role in radar countermeasure and has the ability of large instantaneous bandwidth and multi-signal processing. In order to improve its instantaneous bandwidth, high-speed data acquisition technology is needed. The inherent analog bandwidth of AD chip limits the development of high-speed data acquisition technology. In view of the above problems, this paper proposes a signal processing technology of UWB reconnaissance based on compressed sensing theory. In the process of data acquisition, the limitation of Nyquist sampling theorem is broken, and the sampling rate of AD conversion is reduced. The radar emitter signal can be acquired and measured in a short time. According to the sparse characteristics of radar signal in time, space and frequency domain, the theory of compression sensing is applied to the signal processing of wideband reconnaissance. A broadband digital reconnaissance signal processing scheme based on compressed sensing is proposed. The AIC(Analog-to-Information conversion sampling structure is used to complete the compressed sensing data acquisition of the reconnaissance received signal. The compression times of simple radar signal can reach 32, in which the number of pseudorandom sequences which can be used by Gold codes is more than that of others, and the pseudorandom sequences are selected as pseudo-random sequences to modulate analog signals. In this paper, a signal processing method using parameter estimation algorithm in the back end of AIC structure is proposed. The original signal parameter is estimated directly by using the observation data, which avoids the process of signal reconstruction and improves the speed of obtaining signal parameters to a great extent. The frequency detection range that can be completed is: 10MHz / 16GHz, which basically covers the working band of radar. On the basis of this, a radar pulse signal detection method is studied by combining the estimation of energy threshold and the consistency of frequency. By introducing the zero elimination algorithm based on discrete ellipsoid sequence, the influence of interference frequency band is eliminated, and the overlapping pulse detection and parameter extraction are realized. Finally, the influence of different factors on the signal parameter extraction of the proposed method is analyzed. The main influencing factors include observation matrix, signal density and signal dynamic range, signal-to-noise ratio and compression multiple, and so on. Thus, the general applicable range of UWB signal processing method based on compression perception is obtained.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN957.51

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