Key Technologies of 5G Wireless Communication Network Physical Layer Based on Information Security Early Warning Model

With the continuous development of the fifth generation (5G) technology, the physical layer of the wireless communication network is facing new challenges. How to effectively prevent and protect these key technologies in the physical layer has a great impact on the entire network and even the entire society. Information security early warning model is a state evaluation model of important security control points in the physical layer of communication network. Security is an important indicator of communication system. Whether its security protection is effective is the basis of its survival and use. Aiming at the situation that the receiver is monitored in the transmission system, this paper has studied the safe transmission method assisted by artificial noise (AN). After the simulation experiment of the physical layer security transmission algorithm, this paper discussed the performance of different algorithms in three scenarios: transmission under non ideal channel information, one-way relay eavesdropping system, and multiple input multiple output (MIMO) untrusted relay eavesdropping system. When analyzing the relationship between the safe transmission rate of different MIMO untrusted relay antennas and the target power constraint $A_{T}, M_{y}=5, M_{d}3, M_{t}=4, A_{t}=\{5,35\}$ dB. On this basis, the optimal power distribution was realized. In the six schemes, when the power constraint $A_{T}$ increased, the security transmission rate of each scheme was improved.