宽带中频信号处理系统设计与实现

发布时间：2018-04-22 02:26

本文选题：接收机 + 宽带雷达信号处理　；参考：《哈尔滨工程大学》2014年硕士论文

【摘要】：电子对抗技术在现代信息战中的重要性日益增加,雷达信号的接收和处理是电子对抗技术的研究热点。随着雷达技术的不断发展,现代电磁环境日益复杂,面对信号密集、形势复杂、参数变化快的信号环境,要求电子战接收机具有频率覆盖范围广、灵敏度高、动态范围大、多信号并行处理且满足信号实时性的能力。针对被动雷达信号处理系统的设计,考虑到信道化结构设计和后端信号处理方面,提出了针对宽带中频信号的高精度、实时的信号处理系统设计方案。所设计的宽带中频信号处理系统主要应用在被动雷达系统中,以侦查主动雷达为目标,截获雷达信号后给出信号的相位、频率、信号类型等,并对信号进行测向来确定目标雷达的方位角和俯仰角。在方案设计中,数据采集和信号处理的因素制约着系统性能向更优的方向发展,随着信号带宽的增加,采样率过高不仅对ADC的采样速度和精度提出了更高要求,而且对后端信号处理以及系统设计造成了困难。为了解决上述问题,将传统的测频、测向技术与数字信号处理技术结合起来,采用高精度且采样速度快的ADC及高速FPGA使系统具有精度高、分辨力高、识别能力强等优点。宽带模拟信号首先经过模数转换,信道化过程对高速的数字信号进行降速处理,使得高速采样的宽带信号与FPGA信号处理速度匹配,根据信道化输出的信号IQ信息,得到信号的相位、幅度、频率等,进而进行宽带信号测向和脉内调制特征识别。论文研究的主要内容及创新点如下:首先,本文对宽带中频信号处理系统的关键技术进行研究,推导基于多相滤波的高效信道化结构,仿真验证了该结构的正确性,并且分析了常用的测频算法的测频性能。针对宽带信号的测向问题,本文提出了基于信道化的双频解模糊算法,将宽带信号测向问题与信道化方法进行结合,提高了宽带信号的测向精度。其次,雷达信号的类型识别是雷达信号处理的关键问题,分析了常见的雷达信号类型,针对调频信号和调相信号的脉内特征提出类型识别方法。并提出了V型调频信号和S型调频信号的识别方法,这也是本文的创新点。再次,采用了 ADC和FPGA构建了宽带中频信号处理系统的硬件设计,给出了FPGA的软件设计流程,实现了对宽带中频信号的实时处理,处理时间在10μs以内。最后,在宽带中频信号处理系统硬件测试平台上对其性能进行测试,给出测试结果。
[Abstract]:Electronic countermeasure technology is becoming more and more important in modern information warfare. The receiving and processing of radar signal is the research hotspot of electronic warfare technology. With the continuous development of radar technology, the modern electromagnetic environment is becoming more and more complex. Facing the signal intensive, complex situation and fast parameter change signal environment, the electronic warfare receiver is required to have a wide range of frequency coverage, high sensitivity and large dynamic range. Multi-signal parallel processing and satisfying the ability of real-time signal processing. Aiming at the design of passive radar signal processing system, considering the design of channelized structure and back-end signal processing, a design scheme of high-precision and real-time signal processing system for wideband intermediate frequency signal is proposed. The wideband intermediate frequency signal processing system is mainly used in the passive radar system. The active radar is the target. After intercepting the radar signal, the phase, frequency and type of the signal are given. The azimuth and pitch angle of the target radar are determined by the signal direction finding. In the scheme design, the factors of data acquisition and signal processing restrict the performance of the system to a better direction. With the increase of signal bandwidth, the high sampling rate not only requires higher sampling speed and precision of ADC. It also makes it difficult for the back-end signal processing and system design. In order to solve the above problems, the traditional frequency measurement, direction finding technology and digital signal processing technology are combined, and the high precision and fast sampling speed ADC and high speed FPGA are adopted to make the system have the advantages of high precision, high resolution, strong recognition ability and so on. Wideband analog signal is firstly converted by A / D, and the high-speed digital signal is reduced by the channelization process, which makes the broadband signal sampled at high speed match the processing speed of FPGA signal, and according to the IQ information of signal output by channelization, The phase, amplitude and frequency of the signal are obtained, and then the wideband signal direction finding and intra-pulse modulation feature recognition are carried out. The main contents and innovations of this paper are as follows: firstly, the key technologies of wideband intermediate frequency signal processing system are studied in this paper, and the efficient channelization structure based on polyphase filter is deduced, and the correctness of the structure is verified by simulation. The frequency measurement performance of common frequency measurement algorithms is also analyzed. Aiming at the problem of wideband signal direction finding, a dual-frequency de-ambiguity algorithm based on channelization is proposed in this paper, which combines wideband signal direction finding problem with channelization method to improve the precision of wideband signal direction finding. Secondly, the type recognition of radar signal is the key problem in radar signal processing. The common types of radar signal are analyzed. The recognition method of V type FM signal and S type FM signal is put forward, which is also the innovation of this paper. Thirdly, the hardware design of wideband if signal processing system is constructed by using ADC and FPGA. The software design flow of FPGA is given, and the real-time processing of wideband intermediate frequency signal is realized. The processing time is less than 10 渭 s. Finally, its performance is tested on the hardware test platform of wideband if signal processing system, and the test results are given.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.51

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