Journal of Jilin University(Engineering and Technology Edition) ›› 2021, Vol. 51 ›› Issue (4): 1454-1460.doi: 10.13229/j.cnki.jdxbgxb20200447

Previous Articles    

Improved residual neural network algorithm for radar intra-pulse modulation classification

Zhuo-jun XU1(),Wen-ting YANG2,Cheng-zhi YANG3,Yan-tao TIAN2,4,Xiao-jun WANG1   

  1. 1.School of Aeronautic Science and Engineering,Beihang University,Beijing 100083,China
    2.College of Communication Engineering,Jilin University,Changchun 130022,China
    3.College of Air Force Logistics,Aviation University of Air Force,Changchun 130022,China
    4.Key Laboratory of Engineering Bionics,Ministry of Education,Jilin University,Changchun 130022,China
  • Received:2020-06-19 Online:2021-07-01 Published:2021-07-14

Abstract:

The artificially extracted features are computationally intensive and subjective, fail to fully reflect the nature of the signal, and take too long to generate time-frequency images. To overcome these problems, We propose an improved residual neural network (ResNet) ResNet32 as a framework to extract and identify radar time-domain signal features. We build a time-domain signal dataset of 9 types of intra-pulse signals and input them into the ResNet32 framework for training and classification. The algorithm saves a lot of time to generate time-frequency images, and the experimental verification algorithm has a better recognition rate at low signal to noise ratio (SNR). In the experimental conditions of mixed SNR, the recognition rate of the 9 modulation types with SNR=-14 dB and SNR=-8 dB achieved more than 90%.

Key words: pattern recognition and intelligent system, radar signal, intra-pulse modulation classification, residual neural network

CLC Number: 

  • TP183

Table 1

Phase modulation function"

码型?(t)的定义
2PSK?(t)=0π
4PSK?(t)=0,π/2,π3π/2
P1码

?m(n,k)=-π/LM-(2k-1)(k-1)M+n-1

n=1,2,,Lk=1,2,,L

P2码

?m(n,k)=-π/2L(2n-1-L)(2k-1-L)

n=1,2,,Lk=1,2,,LL为偶数)

P3码?m(k)=π/M(k-1)2k=1,2,,M
P4码?m(k)=π/M(k-1)(k-1-M)k=1,2,,M

Fig.1

ResNet32 structure diagram and ResNet32 residual block structure diagram"

Table 2

ResNet32 parameter settings in proposed method"

参数名称本文ResNet参数设置
卷积核大小[3×1],[5×1],[3×1]
残差块结构
池化方法Max Pooling
损失函数(Loss function)Cross entropy
批量大小(Batch size)16
训练循环次数(Epoch)200
学习率0.001

Table 3

Structure of dataset"

结构内容
调制类型

LFM、2FSK、4FSK、2PSK、

4PSK、P1、P2、P3、P4

信号形式IQ两路信号
样本长度2048采样点
样本维数
信噪比范围-20~20 dB,间隔步长为2 dB
样本个数单信噪比样本个数为1024个

Fig.2

Line chart of recognition rate with single SNR"

Table 4

Comprehensive recognition rates of different algorithms with single SNR"

信噪比/dB

本文识别率/%

ResNet18识别率/%

-20

62.22

41.79

-18

63.22

45.64

-16

65.33

47.13

-14

70.33

50.82

-12

74.33

53.89

-10

74.11

54.99

-8

75.22

60.69

-6

78.89

62.69

-4

84.67

64.19

-2

87.33

67.33

0

92.67

69.22

2

95.78

72.44

4

96.33

72.77

6

96.56

74.76

8

97.22

75.74

10

98.00

81.32

12

98.22

85.13

14

98.78

88.52

16

98.44

89.75

18

98.89

92.33

20

98.44

92.57

Fig.3

Comparison of comprehensive recognition rates of different algorithms with single SNR"

Fig.4

Training loss function and accuracy with mixed SNR"

Table 5

Comprehensive recognition rate after mixed SNR training"

调制类型识别率/%调制类型识别率/%
LFM97P191
2FSK97P297
4FSK98P397
2PSK97P496
4PSK99

Table 6

Comprehensive recognition rates of different algorithms with mixed SNR"

信噪比/dB

本文识别率/%

ResNet18识别率/%

-20

72.02

43.56

-18

79.00

54.00

-16

87.03

67.11

-14

92.90

75.67

-12

97.59

84.44

-10

99.44

92.78

-8

100.00

97.22

-6

100.00

98.63

-4

100.00

99.67

-2

100.00

100.00

0

100.00

100.00

2

100.00

100.00

4

100.00

100.00

6

100.00

100.00

8

100.00

100.00

10

100.00

100.00

12

100.00

100.00

14

100.00

100.00

16

100.00

100.00

18

100.00

100.00

20

100.00

100.00

Fig.5

Recognition accuracy of different SNR"

1 王星, 呙鹏程, 田元荣, 等. 基于BDS-GD的低截获概率雷达信号识别[J]. 北京航空航天大学学报, 2018, 44(3):583-592.
Wang Xing, Guo Peng-cheng, Tian Yuan-rong, et al. LPI radar signal recognition based on BDS-GD[J]. Journal of Beijing University of Aeronautics and Astronautics, 2018, 44(3):583-592.
2 周志文, 黄高明, 高俊, 等. 一种深度学习的雷达辐射源识别算法[J]. 西安电子科技大学学报:自然科学版, 2017, 44(3):77-82.
Zhou Zhi-wen, Huang Gao-ming, Gao Jun, et al. Radar emitter identification algorithm based on deep learning[J]. Journal of Xidian University, 2017, 44(3):77-82.
3 Qu Z Y, Mao X J, Deng Z A. Radar signal intra-pulse modulation recognition based on convolutional neural network[J]. IEEE Access, 2018, 6:43874-43884.
4 Qin X, Zha X, Huang J, et al. Radar waveform recognition based on deep residual network[C]∥IEEE 8th Joint International Information Technology and Artificial Intelligence Conference, Chongqing, China, 2019:892-896.
5 胡国兵, 宋军, 李昌利. 低截获概率雷达侦察信号分析及可信性评估[M]. 北京:国防工业出版社, 2017.
6 樊昌信. 通信原理[M]. 北京:国防工业出版社, 2009.
7 张贤达. 通信信号处理[M]. 北京:国防工业出版社, 2000.
8 刘峰, 黄宇, 王泽众, 等. 复杂信号侦察理论及应用[M]. 北京:科学出版社, 2016.
9 王彩云, 何志勇, 宫俊. 基于压缩感知的单脉冲雷达欺骗干扰机研究[J]. 北京航空航天大学学报, 2017, 43(9):1789-1797.
Wang Cai-yun, He Zhi-yong, Gong Jun. Research on deception jammer against monopulse radar based on compressed sensing[J]. Journal of Beijing University of Aeronautics and Astronautics, 2017, 43(9):1789-1797.
10 He K M, Zhang X Y, Ren S Q, et al. Deep residual learning for image recognition[C]∥IEEE Conference on Computer Vision and Pattern Recognition (CVPR), Seattle,USA, 2016:770-778.
11 Zhang Y B, Sun L L, Yan C G, et al. Adaptive residual networks for high-quality image restoration[J]. IEEE Transactions on Image Processing, 2018, 27(7): 3150-3163.
12 李琳辉, 伦智梅, 连静,等. 基于卷积神经网络的道路车辆检测方法[J]. 吉林大学学报:工学版, 2017,47(2):384-391.
Li Lin-hui, Zhi-mei Lun, Lian Jing, et al. Convolution neural network-based vehicle detection method[J]. Journal of Jilin University (Engineering and Technology Edition), 2017, 47(2):384-391.
13 Wen Z G, Liu D, Liu X Q, et al. Deep learning based smart radar vision system for object recognition[J]. Journal of Ambient Intelligence and Humanized Computing, 2019,10:829-839.
14 Li B Q, He Y Y. An improved ResNet based on the adjustable shortcut connections[J]. IEEE Access, 2018, 6:18967-18974.
15 郭坚, 漆轩. 基于残差网络的自动调制识别[J]. 计算机工程与设计, 2019, 40(9):2406-2410.
Guo Jian, Qi Xuan. Automatic modulation classification based on residual network[J]. Computer Engineering and Design, 2019, 40(9):2406-2410.
[1] Fu LIU,Lu LIU,Tao HOU,Yun LIU. Night road image enhancement method based on optimized MSR [J]. Journal of Jilin University(Engineering and Technology Edition), 2021, 51(1): 323-330.
[2] LIU Fu, LAN Xu-teng, HOU Tao, KANG Bing, LIU Yun, LIN Cai-xia. Metagenomic clustering method based on k-mer frequency optimization [J]. Journal of Jilin University(Engineering and Technology Edition), 2018, 48(5): 1593-1599.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!