Design And Analysis Of Low Probability Of Detection Signal In WFRFT Transform Domain

With the rapid development of information and communication technology,people's requirements for the security performance of communication systems are increasing day by day,and information security issues have received special attention and research.At present,the mainstream confidentiality mechanism mainly relies on encryption methods with cryptography as the core.Its development is very mature and has been widely recognized and applied.However,the existing security assurance system still has room for improvement in the detection of physical layer waveform resistance.With the deepening of research,the physical layer security technology as an effective supplement to the upper layer encryption system has shown important research value.In recent years,weighted fractional Fourier transform has been gradually introduced into the field of physical layer security research a s a signal processing method with complete theoretical system,lower complexity and easy engineering implementation.In this paper,for the further enhancement of its anti-interception performance,a safe transmission method based on multiple extended weig hted fractional Fourier transform is proposed.By constructing a new form of low detection probability signal in the transform domain,the safety performance of the system is improved.Aiming at the existing fractional domain anti-interception scheme,this paper studies its safety mechanism,and explains its existing problems and improvement directions.Based on the further improvement of system security performance,this paper proposes a multiple extended weighted fractional Fourier transform,and gives its realization method and satisfying mathematical properties.It shows that it has the feasibility of introducing wireless communication system and the advantage applied to the anti-interception of signals.A model of a secure communication system based on multiple extended weighted fractional Fourier transform is established,and the basic characteristics,statistical characteristics and multi-component self-interference characteristics of its signals are studied.Theoretical analysis and simulation verific ation illustrate the contribution of the proposed method to the safety performance of the system.On this basis,based on the improvement of the anti-scanning ability of the existing fractional domain transform form,this paper proposes an anti-parameter scanning method based on multiple extended weighted fractional Fourier transform.The demodulation performance of the proposed method is analyzed with the indicators of equivalent signal-to-noise ratio and bit error rate.The research results show that the extended weighted transform achieves an effective increase in the parameter dimension,and the proposed method greatly improves the parameter anti-scanning ability of this type of transform.At the same time,this paper studies the signal anti-modulation recognition ability under the existing fractional domain transform form,and points out its mechanism and existing security risks.In order to improve its performance,a signal anti-modulation recognition method based on multiple extended weighted fractiona l Fourier transform is proposed,and its principle is explained.The analysis shows that the proposed method creates difficulties for signal interception and effectively improves the system safety performance.