Research On Wireless Communication Physical Layer Security Technology

Due to the nature of wireless communications and broadcasting, as well as applications and high-density non-resource constraints, particularly in the per-ception and mobile networks, the wireless communication has become very vulnerable to a variety of attacks, which contains message tampering, eaves-dropping, network attacks, and malicious forwarding. Although wireless net-works, traditional encryption is very important, and plays a vital role in resisting attacks, but because of the existence of both a theoretical and practical signifi-cance, and provides the potential to strengthen the security of the wireless communication system physical layer approach to security, wireless physical layer communications security so get new attention. In most cases, the wireless communication under the safety analysis, are divided into complete channel state information and imperfect channel state information in both cases. Under perfect channel state information scene, the sender can get optimal signal transmission scheme to obtain a reliable means of communication. Under im-perfect channel state information condition, the sender cannot get complete conditional message such as channel transfer matrix, user’s location and so can only be estimated through, or beamforming way to try to reduce the eavesdrop-per can receive information when sending correspondence.At present, although in small scale analysis of results with a considerable degree, but in large-scale networks, is still in an initial stage, at the same time, in the absence or partial (imperfect) Safety analysis under the conditions of the channel state information, the same is worthy of in-depth exploration of this field. This paper describes several methods to solve the physical layer for secure communications, LDPC code method, relay method, beamforming methods e.t.c, and compare the similarities and differences of these methods, analysis the potential problems and limitations in these methods. The results show that both of the LDPC code method, a relay method, etc., can not be applied to large-scale networks, and in fact, these methods are used only for small scene secure communication.The innovation is that the subject is given a new secure communication scenarios, namely the introduction of the package cavity eavesdropping user communication networks, and for tapping between the user and the base station introduces correlation assumptions, while ignoring the interference between us-ers. On this basis, assuming that all communication terminals are Poisson point processes and stochastic geometry approach to analyze the capacity of the entire network security at the base station when the observed radius distribution of fi-nite and infinite.Finally, comparing simulation results verify the theoretical analysis shows t security capacity exists when the association between base station and the eavesdropper is assumed. And the simulation results and the resulting formulas are consistent, indicating that the capacity will be less than the income security without the associated assumptions security capacity, and is not associated as-sumptions on income security capacity is lower correlation assumptions infi-mum security capacity. At the same time, the simulation results also show that, for a limited observation station area, that is the base station can observe whether or not the eavesdropper exist, when other parameters remain unchanged, observation area with a radius of infinite capacity of the security reach its su-premum The simulation results also show that, in eavesdropper high-density distribution network, changing the remaining parameters are unable to improve security capacity, the same is to legitimate recipient (mobile users) high-density distribution network, the security capacity change is not significant with the changes in other parameters.proved.