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Method and device for suppressing multi-component frequency modulation interference in a spread spectrum communication system

A technology of frequency modulation interference and spread spectrum communication, which is applied in transmission systems, electrical components, etc., and can solve problems such as inability to effectively eliminate interference and inability to effectively suppress

Active Publication Date: 2021-05-14
HENAN MECHANICAL & ELECTRICAL VOCATIONAL COLLEGE +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when the interference is a non-linear frequency modulation signal, the fractional Fourier transform still cannot effectively eliminate the interference
[0010] Multi-component non-linear frequency modulation interference can improve the interference effect more effectively, but the above methods cannot effectively suppress this kind of interference, so it is necessary to develop a method and device that can suppress multi-component non-linear frequency modulation interference

Method used

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  • Method and device for suppressing multi-component frequency modulation interference in a spread spectrum communication system
  • Method and device for suppressing multi-component frequency modulation interference in a spread spectrum communication system
  • Method and device for suppressing multi-component frequency modulation interference in a spread spectrum communication system

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Embodiment 1

[0111] The spread spectrum ratio of the system is set to 15, the spread spectrum code adopts m sequence, 200 bits of data are sent in each frame, the power of the sent signal is fixed at 0dB, and the bit signal-to-noise ratio is 10dB. The wavelet function takes a compactly supported biorthogonal wavelet 'sym8' with approximately symmetrical characteristics, and uses a fast wavelet packet transform algorithm. The interference signal is a combination of a linear frequency modulation signal and a nonlinear frequency modulation signal, and the normalized initial frequency of the linear frequency modulation signal is is 0.2, the normalized frequency modulation rate is =0.00004, the normalized initial frequency of the non-linear frequency modulation signal is 0.1, and the 2.5 power frequency modulation is adopted, and the normalized frequency modulation rate is 0.000001.

[0112] Figure 3 is a wavelet envelope color coefficient map, Figure 3a , Figure 3b , Figure 3c , Figure ...

Embodiment 2

[0115] The spread spectrum ratio of the system is set to 15, the spread spectrum code adopts m sequence, 200 bits of data are sent in each frame, the power of the sent signal is fixed at 0dB, and the bit signal-to-noise ratio is 10dB. The wavelet function is a compactly supported biorthogonal wavelet 'sym8' with approximately symmetric properties, and a fast wavelet packet transform algorithm is used. The interference signal is a combination of two non-linear frequency modulation signals. The normalized initial frequency of the first non-linear frequency modulation signal is 0.15. The normalized initial frequency is 0.1, the third power frequency modulation is adopted, and the normalized frequency modulation rate is 0.00000001.

[0116] Figure 5 is a diagram of wavelet envelope color coefficients, Figure 5a , Figure 5b , Figure 5c , Figure 5d The number of decomposition layers are 3, 4, 5, 6 respectively, where g 3 =2.5, g 4 =3.5, g 5 =4.4,g 6 = 4.4, Image 6 is t...

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Abstract

The present invention relates to the field of spread spectrum communication systems, and specifically discloses a method and device for suppressing multi-component frequency modulation interference in a spread spectrum communication system. The device includes a chip matching filter module, a sampling module, a delay buffer module, a decomposition layer determination module, and a threshold Filtering module, wavelet packet reconstruction module and despreading judgment module; the main steps of the suppression method are: first carry out chip matching filtering and then carry out chip rate sampling, cache the sampled signal, and determine the optimal wavelet packet decomposition according to the degree of energy aggregation According to the number of layers, calculate the threshold value according to the wavelet packet decomposition coefficient, then perform threshold filtering, then perform wavelet packet reconstruction, despread and judge the signal after interference cancellation, and receive data. The present invention has the following advantages: the present invention utilizes the multi-resolution analysis ability and good time-frequency localization characteristics of wavelet packet transform to quickly locate the multi-component nonlinear frequency modulation interference in a certain time-frequency unit, and realize the separation of interference and signal, Thereby eliminating interference.

Description

technical field [0001] The invention belongs to the field of spread spectrum communication systems, in particular to a method and device for suppressing multi-component frequency modulation interference in a spread spectrum communication system. Background technique [0002] Due to its unique advantages, spread spectrum communication systems are widely used in both civil and military fields. How to suppress intentional interference and ensure smooth communication in the military field has always been an important topic. FM interference is a kind of non-stationary broadband interference , which can effectively suppress the normal communication of the spread spectrum communication system, and is an important threat to the spread spectrum communication system. [0003] There are mainly the following methods for suppressing FM interference: [0004] (1) Wigner transformation [0005] The Wigner transform has the best time-frequency aggregation for FM signals, and is very suita...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04B1/69H04B1/7097
CPCH04B1/69H04B1/7097
Inventor 张玉恒何明刘志青彭浩
Owner HENAN MECHANICAL & ELECTRICAL VOCATIONAL COLLEGE