Research On Jamming Identification Technology Of Wireless Communication

With the rapid development of wireless communication technology,electronic warfare has become the main position of modern war.The enemy often degrades the quality of our tactical communications through malicious interference.Effective identification of jamming signal patterns and estimation of jamming signal parameters play a key role in military wireless communication,which provides necessary information for communication anti-jamming.This paper focuses on the pattern classification of common jamming signals and wideband spectrum sensing of disturbed signals.Firstly,the paper summarizes the whole flow of communication interference identification.Then this paper analyzes the generation mechanism of common jamming signals and carries on mathematical modeling and simulation analysis,including the basic jamming and responsive jamming such as single-ton jamming,wideband noise jamming,comb spectrum jamming,phase reversal jamming,amplitude modulation jamming and continuous wave jamming.In order to improve the practical significance of this research,this paper takes data link system as the simulation background.This research focuses on key technologies such as continuous phase modulation,soft spread spectrum coding and frequency hopping modulation in order to restore the data link signal.Then the paper studies the feature based interference pattern recognition algorithm,which is divided into three parts:preprocessing,feature extraction and classification.After the data is normalized and centralized,several signal processing methods such as Fourier transform are applied to extract the time-frequency characteristics of all kinds of jamming signals like R parameter,C parameter,Fse parameter and ₃b parameter.According to the features extracted,decision tree and support vector machine（SVM）are used for training and classifying.Simulation results show that the recognition algorithm performs well and the classification accuracy is greater than 95%at low JNR.In order to provide more prior information for communication anti-jamming,this paper carries out broadband spectrum sensing for disturbed signal which aims at accurately detecting the distribution of disturbed signal in the spectrum sensed,The number,bandwidth,central frequency points and other information of the sub-signals should be known.Frequency hopping technology expands the occupied frequency band and improves the anti-jamming performance of data link.But it also bring great challenges to spectrum sensing.This paper analyzed the principle of wavelet edge detection and its application in broadband spectrum sensing in detail.Considering the situation that several sub-signals with different bandwidth exist during the frequency range at the same time and the spectrum of interest is not flat,this paper establishes a representative signal model and proposes a broadband spectrum sensing algorithm based on multi-scale wavelet fusion decision who can complete the task of broadband spectrum sensing in complex situation by setting the candidate set of transform scale reasonably,fusing the detection results at all scales effectively and processing the sub-signals with different bandwidth successively.Simulation results show that the proposed algorithm can effectively detect the communication parameters of interest and performs better than the traditional wavelet edge detection algorithm.Finally,the paper develops an"intelligent interference recognition software"based on the above research results.The software provides a visual operation interface,which can recognize the generated jamming signals and detect the distribution of the received signals in the frequency band of interest.