雷达通信一体化信号识别研究

发布时间：2018-05-12 00:41

本文选题：雷达通信一体化 + 信号识别　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：由于现代电子战中各种电子设备的增多,雷达通信一体化设备是现在乃至将来的发展趋势。雷达通信一体化信号兼具雷达信号和通信信号的特点,通过把通信信息调制到雷达信号载波上,利用雷达收发设备完成信号的发送和接收,再利用软件无线电合成或分解雷达信号和通信信号。因此,雷达通信一体化不仅提高了通信信号的保密性和抗干扰能力,而且实现了雷达和通信系统的自动化和网络化。本文针对目前雷达信号识别研究中存在的技术性问题,对现有雷达信号识别中的关键算法进行了改进,并结合雷达通信一体化信号的特征,对雷达信号和通信信号的识别进行了研究。具体研究内容介绍如下:1.在电子侦察中,脉冲信号重频模式的识别是在分选后进行的,而分选结果的好坏直接决定了重频模式识别的准确度。由于谐波干扰和参数测量的偏差问题,分选后的脉冲信号存在不同比例的寄生脉冲,而目前重频模式识别算法对存在寄生脉冲的情况识别率都不高。因此,针对雷达信号典型的六种重频模式,本文提出了一种基于符号法识别重频模式的方法。通过把PRI序列和DPRI序列符号化,并对符号化后的序列进行编码,从编码序列中提取出四个特征参数,分别为F、H、C和P,四个参数分别与对应门限值比较,进而识别六种重频模式。仿真结果表明:在寄生脉冲所占比例从0~20%的情况下,对六种重频模式均有高达95%以上的识别率。2.现代新体制雷达信号具有强稳定性的特点,即相参性。目前,相参性识别方法中抗噪声性能最好的为时域自相关法,但该方法只能从图像上识别相参信号,不能实现识别自动化,为此,本文提出了改进时域自相关法。通过改进延迟器,实现了对非固定重频信号的处理;通过把经过滤波的脉冲信号符号化并编码,并利用统计学中的平均自信息量从编码序列中提取H1参数,进而区分相参信号和非相参信号。本文在重频模式分别为固定重频和上滑变重频,以及脉内调制方式分别为单一正弦波调制和线性调频的情况下做了对比实验,仿真结果表明:在不同的重频模式和脉内调制类型条件下,当信噪比大于等于5dB时,对相参信号和非相参信号的识别率高达95%以上。3.雷达信号和通信信号最本质的区别是脉内调制方式不同。本文选用的雷达信号调制类型为单一正弦波调制、线性调频、正弦调频和4PSK调制,并选用调制方式为MSK的通信信号进行研究。经过研究,修正了快速离散分阶数傅立叶变换,并提出了一种基于分阶数傅立叶变换的脉内调制类型识别方法。信号经FRFT变换可以得到p-v曲线,并从中提取H2和H3参数,经门限比较可以实现自动化识别。仿真结果表明:在高斯白噪声下,当信噪比大于等于5dB时,对五种脉内调制方式有高达95%以上的识别率。
[Abstract]:Due to the increase of various electronic equipments in modern electronic warfare, radar communication integration equipment is the development trend now and even in the future. The integrated radar communication signal has the characteristics of both radar signal and communication signal. By modulating the communication information onto the radar signal carrier, the radar transceiver equipment is used to transmit and receive the signal. Then software radio is used to synthesize or decompose radar signal and communication signal. Therefore, the integration of radar communication not only improves the confidentiality and anti-jamming ability of communication signal, but also realizes the automation and networking of radar and communication system. Aiming at the technical problems existing in the research of radar signal recognition, this paper improves the key algorithms of radar signal recognition, and combines the characteristics of radar communication integrated signal. The recognition of radar signal and communication signal is studied. The specific contents of the study are as follows: 1: 1. In electronic reconnaissance, the recognition of repetition mode of pulse signal is carried out after sorting, and the accuracy of pattern recognition of repetition frequency is directly determined by the result of sorting. Because of the problem of harmonic interference and the deviation of parameter measurement, there are different proportion of parasitic pulse in the separated pulse signal, but the recognition rate of the current repetition pattern recognition algorithm for the case of parasitic pulse is not high. Therefore, aiming at the six typical repetition modes of radar signal, this paper presents a method based on symbol method to identify the repetition mode. By symbolizing the PRI sequence and the DPRI sequence, and coding the symbolized sequence, four characteristic parameters are extracted from the coded sequence, namely, FG Heng C and P respectively. The four parameters are compared with the corresponding threshold values respectively, and six repetition modes are identified. The simulation results show that when the proportion of parasitic pulses is from 0 to 20%, the recognition rate of more than 95% is obtained for all the six repetition modes. The radar signal of modern new system has strong stability, namely coherence. At present, the best anti-noise method is time-domain autocorrelation method, but this method can only recognize coherent signals from images, so it can not realize automatic recognition. Therefore, an improved time-domain autocorrelation method is proposed in this paper. By improving the delayer, the processing of the unfixed repetition signal is realized, the filtered pulse signal is symbolized and encoded, and the H1 parameter is extracted from the coding sequence by using the average self-information in statistics. Then the coherent signal and the non-coherent signal are distinguished. In this paper, a comparative experiment is made under the condition that the repetition mode is fixed repetition frequency and the up-slip variable repetition frequency, and the intra-pulse modulation mode is single sine wave modulation and linear frequency modulation, respectively. The simulation results show that the recognition rate of coherent and non-coherent signals is over 95% when SNR is greater than or equal to 5dB under different repetition modes and intra-pulse modulation types. The essential difference between radar signal and communication signal is that the modulation mode is different. In this paper, the modulation types of radar signal are single sine wave modulation, linear frequency modulation, sine frequency modulation and 4PSK modulation, and the communication signal with MSK modulation is studied. The fast discrete fractional Fourier transform (FFT) is modified, and a method of intra-pulse modulation type recognition based on split-order Fourier transform is proposed. The p-v curve can be obtained by FRFT transformation, and the H _ 2 and H _ 3 parameters can be extracted from the p-v curve. The simulation results show that when the SNR is greater than or equal to 5dB under Gao Si white noise, the recognition rate of the five intra-pulse modulation schemes is up to 95%.
【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】：2014
【分类号】：TN957.51

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