Physical Layer Secure Transmission Based On Spatial Modulation

In recent years,communication technology is innovating at a rapid speed and wireless communication is free from the shackles of wired,but its open communication media has brought great hidden trouble to the security of wireless communication.Therefore,the information security in wireless communication has become an important issue of people's attention and has become a hot research issue in academia and industry.The traditional method of information security is encryption and authentication based on key.For wireless communication,due to legal physical channel between the receiver and the eavesdropper natural existence difference,this difference can be used to realize the physical safety transmission.In recent years,academic circles have paid more and more attention to the problem of realizing information secure transmission based on physical layer characteristics.Current researches on physical layer security mainly focuse on artificial noise,beamforming,multi-antenna gapping,etc.The design of transmit signal codebook based on channel can effectively prevent eavesdroppers from cracking information,but these researches are based on ideal assumptions such as the eavesdropper's inability to know the channel information,and there are certain security risks.Therefore,how to make good use of channel information to design more secure transmit signals is the focus of this thesis.The work of this thesis focuses on the secure transmission of the physical layer based on multi-antenna systems.Specifically,this thesis mainly studies the secure transmission of the physical layer based on spatial modulation.From different perspectives,it studies the applicable security schemes in different scenarios,and verifies the security of the proposed schemes by means of simulation and theoretical proof.The main work and innovations of the thesis are as follows:1.Propose a secure transmission scheme based on random precoding.This scheme expands the signal codebook into an infinite set,and combines random selection at the same time,thereby significantly enhancing security.The thesis analyzes the symbol error rate performance of the proposed scheme theoretically and gives an approximate solution.Theoretical analysis and simulation verification show that the security performance of the proposed scheme is significantly better than the existing technology.2.A secure scheme based on power adaptation is proposed.The scheme can adjust the transmission power adaptively,reduce the power when the signal-to-noise ratio is high,and increase the power when the signal-to-noise ratio is low,and adjust the power for different transmission signalsso that the scheme can not only guarantee the QoS,but also better guarantee the security.The thesis verifies the performance of the scheme through simulation.3.A secure scheme based on feedback control is proposed.Under the time division duplex system,this scheme can not only increase the transmission rate,but also avoid the leakage of channel information.This scheme greatly increases the difficulty of eavesdropping through the dynamic joint encryption of the sender and receiver,and combines the use of artificial noise technology to enhance security.The thesis verifies the performance of the scheme through simulation.