【作者】 龙柯宇；

【导师】 唐斌；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2012， 博士

【摘要】 随着各种新体制、新技术在雷达系统中的广泛应用，雷达侦察任务的复杂性日益凸显。现代雷达极宽的工作带宽、复杂多变的信号形式、更隐蔽的收发体制等新特性给雷达侦察接收机在信号截获、参数估计、辐射源分选、多信号处理方面提出了极大的挑战。面对现代复杂的侦察电磁环境，侦察接收机必须具备宽的瞬时截获带宽以截获各类雷达信号；具备大的瞬时动态范围，以应对高密度脉冲流条件下时频混叠脉冲以及复杂调制脉冲的多个同时到达强弱信号的截获；具备复杂调制信号的参数估计及识别能力以满足新体制雷达的侦察需要。针对以上雷达侦察接收机需求，本文在现有器件水平条件下，对实现宽瞬时带宽及高瞬时动态范围的新型接收机结构进行了研究，改进和提出了宽带信号截获方法，并主要针对复杂调制信号脉内参数估计及辐射源波达方向（DOA）估计等两个雷达侦察接收关键技术进行了研究。最后，本文基于相关课题，对其中的部分算法在实际工程中进行了验证。本文的研究工作和主要创新如下：1．针对超宽频段信号截获问题，本文研究了Nyquist折叠接收机（NYFR）原型结构，分析并总结出该采样结构所蕴含的超宽频段信号截获机理，在此基础上提出了基于通道编码、双本振和多本振的NYFR改进结构。这些改进结构解决了原型接收结构不能保证Nyquist区域（NZ）估计的存在和唯一性问题，并扩展了该类接收机能适用的信号类型，降低了工程实现难度。本文同时给出了基于该改进结构的频率捷变（FA）信号和线性调频（LFM）信号的参数估计方法。2.针对宽带、大动态信号截获问题，本文从解欠采样频域模糊思路出发，提出了一种基于相位匹配原理（SPMP）的宽带信号截获结构。该结构采用多片低速率、高精度模数转换器（ADC）对宽带、大动态范围信号进行多通道并行采样，再通过相位匹配算法对多路采样数据解欠采样频域解模糊，从而获得宽带信号的低失真重构。该宽带信号截获结构具有子信道可无缝拼接、对器件参差不敏感、易于工程实现等特点。3.针对复杂调制雷达信号侦察，本文基于直接序列扩频通信中的子脉冲同步方法，研究了在脉冲不同步情况下，线性调频-伪码（LFM-PRBC）卷积复合调制信号的参数估计算法。4.针对旋转载体上的被动雷达信号DOA估计问题，研究了一种适用于宽频段的双阵元旋转基线DOA估计技术，并结合特定信号环境，提出了工程适用的解测向模糊算法，与同类方法相比，具有解模糊概率高、运算量小、易于实现等特点。5.研究了被动雷达信号处理机原理样机的系统设计和硬件实现，其中包括原理样机的总体方案设计，以及双通道信道化处理板、参数估计处理板的研制。测试结果显示该原理样机满足设计指标，系统稳定可靠。更多还原

【Abstract】 Along with wide applications of new systems and technologies in radardevelopment, the task of radar reconnaissance becomes more and more complex. Themodern radar has ultra-wide bandwidth, complicated signal form, and covert transceivermechanism, making signal interception, parameter estimation, radiation sourceclassification, and multi-signal processing in the radar reconnaissance receiver be atremendous challenge. Facing the modern complex reconnaissance environment, thereconnaissance receiver must have the wide instantaneous interception bandwidth tointercept various radar signals, wide instantaneous dynamic range to deal with theinterception of pulses mixed in time-frequency domain in the case of high density pulsestream and non-equal power complex modulated pulses which arrive at the same time,and ability of parameter estimation and recognition of the complex modulated signal tomeet the requirement of new systems radar reconnaissance. Aiming at these problems,in current level of hardware, this thesis researches the structure of the new type receiverwhich achieves wide instantaneous bandwidth and wide dynamic range, improves andproposes the interception method for the wide signal, and researches several keytechnologies in radar reconnaissance receiving such as intra-pulse parameter estimationof complex modulated signals and direction of arrival (DOA) estimation of the radiantsource. Finally, based on some relevant projects, this thesis verified part of algorithms inengineering environments.The main researches and contributions of this thesis are as follows:1. Aiming at the problem of ultra-wide band signal interception, this thesisresearches the structure of the Nyquist folding receiver (NYFR) prototype anddemonstrates the principle of interception of the ultra-wide band signal in this samplingstructure. From this analysis, we propose an improved NYFR structure based on thechannel coding, double local oscillators, and multiple local oscillators. These improvedstructures figure out the problem that the original receiving structure cannot assure theexistence and uniqueness of the Nyquist zone (NZ) estimation, extend the applicablesignal types of the receiver, and reduce difficulty of engineering realization. Besides, this thesis also gives the parameter estimation algorithm for the frequency agility (FA)signal and the linear frequency modulation (LFM) signal based on this improvedstructure.2. Aiming at the problem of wide band and wide dynamic range signal interception,this thesis proposes a wide band signal interception structure based on the signal phasematching principle (SPMP) from the idea of solving frequency ambiguity in the case ofundersampled signals. This structure uses parallel multiple low velocity and highprecision analog-to-digital converters (ADCs) to sample wide band and wide dynamicsignals in multiple channels. Subsequently, to get the low distortion reconstruction ofthe wide band signal, we solve frequency ambiguity in the case of multi-channelundersampled signals using the SPMP algorithm. This wide band signal interceptionstructure has the properties of seamless connection of sub-channels, non-sensitivity ofdevice differences, easy to implement in engineering, and so on.3. Aiming at the problem of reconnaissance of the complex modulated radar signal,this thesis researches parameter estimation of the convolutive signal combined LFM andPRBC (LFM-PRBC) hybrid modulated signal in the pulse asynchrony situation basedon the sub-pulse synchronization method in direct sequence spread spectrumcommunication.4. Aiming at the problem of radar signal DOA estimation on rotating carrier, thisthesis proposes a direction finding technology based on double antennas rotatingbaseline which is applicable in wide frequency range and researches a solving directionambiguity algorithm for the specific signal environment. As opposed to the similarmethods, this one has the properties of high probability of solving ambiguity, easy toimplement, and so on.5. This thesis researches the system design and hardware implementation ofpassive radar signal processor pricinple prototype, including overall scheme design ofthe pricinple prototype and development of the ADC and digital channelized board andthe parameter estimation board. The testing results show that this pricinple prototypemeets the design index and the system is stable and reliable.更多还原