The Research Of Future Wireless Enhanced Secure Communication Based On Physical Layer

Future wireless communication system(5G) is proposed for high-speed transmission, fast access, good user experience and high security requirements, the traditional security measures have been unable to meet the requirements. The physical layer security technology based on the essence of wireless communication, makes full use of the wireless channel characteristic,and makes the reliable communication security technology and communication technology combined to consider. In 5G system by utilizing 5G new technology combining the physical security the physical signal design, can achieve high security transmission, and meet the needs of rapid access.MIMO-OFDM is the core technology of 4G, in the Massive MIMO of 5G communication in the future, MIMO-OFDM is still the basic technology and key technology. Spatial modulation technology is an important branch of MIMO technology, it can completely avoid the multiple antenna transmitting at the same time the inter-channel interference and transmitting antenna need synchronization problems, significantly improve the utilization rate of frequency will be an important direction of the MIMO technology development in the future. This thesis based on the physical layer transmission technology did the physical layer security signal design, and did the experiment on the USRP.Firstly, this thesis puts forward the implementation of the "unconditional secret communication" through two steps, and designs a feasible scheme. First by SVD decomposition of beamforming the scheme fully takes advantage of the randomness of wireless channel makes the legitimate user channel established, and then designe a function based on springback to construct the security code to further increase the BER of eavesdropper. Based on the spatial modulation technology of MIMO technology, and tried to use the traditional symbol for cross-layer scheme on the cross layer, and found the problem and the insufficiency. By studying the particularity of spatial modulation technology, and then put forward at the same time to launch symbols and transmitting antenna number across the layer, its feasibility is verified by simulation and the principle. Finally, this thesis discusses the OFDM encryption cross layer security transmission technology, and through the USRP with LABVIEW software successfully verified its feasibility. In this thesis, the proposed scheme can be used for 4G, which is advantageous for 5G compatible with 4G. Without significantly increasing system overhead, the new security mechanism has high safety performance, giving attention to reliability and security of the communication system.