Satellite Communication Physical Layer Security Scheme And Simulation Based On The Combination Of Scrambling Coding And HARQ

With the continuous development of satellite mobile communication technology and space-based broadband integrated services digital communication network technology,satellite communication technology is more and more widely used in economic,social and defense military fields.However,due to the openness of information dissemination,the security threats it faces are becoming more and more serious.So it is urgent to study the security technology of satellite communication network.Firstly,this paper analyses the composition,characteristics and working principle of satellite communication,establishes the model of eavesdropping channel in satellite communication based on classical eavesdropping channel model.On this basis,?and?designs a secure transmission scheme in physical layer of satellite communication by combining secure coding technology with HARQ protocol.In this scheme,the information to be transmitted is coded confidentially and then sent to the satellite.The satellite works in the way of storage and forwarding.The ground legal user interacts information with satellite through the HARQ method during the working process,while the eavesdropping user can only passively receive the information.The theoretical analysis shows that the scheme can effectively utilize the randomness and difference of the noise of legitimate channel and eavesdropping channel to realize the secure transmission of legitimate user information.In this paper,the simulation model of the scheme is established by using Simulink simulation tool,and the scheme is simulated and analyzed in detail by reasonably choosing simulation parameters.The simulation results show that when the scrambling length is 9216,the short frame length is 288 and the maximum number of retransmissions is Q_MAX=3,there is a security window with a width of 1.58dB?signal-to-noise ratio?.When the received signal-to-noise ratio of the legitimate user is within the window,reliable communication can be achieved.At this time,the error rate of the illegal receiver will be more than 0.4,and the effective information can not be obtained,thus the security of the legitimate user can be realized.This result shows that the satellite secure communication scheme designed in this paper has good feasibility and effectiveness.