Identification And Generation Of Communication Signals In The Electromagnetic Environment

The reproduction of electromagnetic environment signals is the basis for studying the effects of equipment on complex electromagnetic environments.As the most common electromagnetic signal,The communication signal is the primary task of constructing the electromagnetic environment signal.Therefore,the main work of this paper is to build electromagnetic environment signals based on communication signals.The generation of communication signals mainly includes the generation of typical signals and the reproduction of acquired signals.For a typical communication signal,it is generated by means of IQ modulation.for the acquisition signal,analysis and reproduction are performed by the method of IQ complex decomposition and signal recognition regeneration.In order to establish a unified generation model for two different signal generation methods,the typical communication signal generation is regarded as the acquisition of the acquisition signal with known modulation parameters and modulation types.This article takes any collected signal as the main research object,first recognizes the signal,and then generates it according to the typical signal generation method.And directly generates the signal that cannot or does not need to be identified according to IQ metathesis.Therefore,this article is divided into three parts: signal recognition,signal generation,and software implementation:The first part is the research of signal recognition technology based on BP neural network.Firstly,it summarizes the identification methods of various communication signals,and selects the identification method based on statistical features;then,based on matlab,it realizes the wavelet denoising of the signal;then the signal is subjected to Hilbert transform to extract the signal's characteristic parameters,and further constructs.The characteristic parameters of the signal;Finally,based on the characteristic parameters of the signal as the decision basis,the signals under different SNRs are identified and analyzed by the BP neural network,and the feasibility of signal recognition by the BP neural network is obtained through the recognition rate.The second part is the research of signal generation method.First,a signal generation framework for general communication equipment was built.For the generation of communication signals,the main work is the modulation method of communication signals.This article lists the IQ modulation components of common analog signals and digital signals,and IQ for any signal.The metathesis is described in detail.In order to simulate the communication signal more accurately,we simulated the propagation of the signal in the channel and realized the generation of Gaussian white noise.We also performed a simple analysis of the commonly used digital filters.The third part is the realization of the signal generator tool based on arbitrary waveform generator.Combining the first two parts of the theory,this paper designs and implements the electromagnetic environment signal generation tool through C/C++/C#/MATLAB programming.And control the arbitrary waveform generator and actually generates electromagnetic signals.The electromagnetic environment signal generating tools mainly include signal analysis and instrument control software.,communication signal generation software and database in three parts.In the future work will gradually improve the communication counter signal,radar signal storage and software preparation.