Research On MIMO Wiretap Channels Secure Performance Based On Antenna Correlation

People have always been pursuing the secure transmission of information,however, as the open nature of wireless network and the rapid increase of the number of wireless terminals, it is difficult for people to prevent the interference and eavesdropping. In recent years, due to the wide use of multiple-input multiple-output(MIMO) technology in wireless networks, the security problems of MIMO technology have become more and more prominent in civil and military fields.Traditionally, encryption methods have been designed and implemented to provide security in the upper layers, while assuming that the physical layer can provide good security link, as a supplement of upper layer encryption method, this paper is from the point of view of the physical layer to analyze how to realize the secure communication. Different from the traditional encryption method, the physical layer security of wireless communication is addressed from an information theoretic perspective and is given the implementation feasibility of secure transport in the MIMO eavesdropping channel model. In MIMO system, the antenna correlation is affected by the arrangement of the antennas and the signal arrival angle, so antenna correlation must be considered in designing system. We analyze the impact of antenna correlation on secrecy performance of MIMO wiretap channels where transmitter employs the best transmit antenna selection(TAS) and general-order TAS while receiver and dropper perform maximal-ratio combining(MRC). The main work and research results are as follows:The first, we analyze the impact of the best TAS and MRC on secrecy performance of MIMO wiretap channels. New closed-form expressions are derived for the secrecy outage probability and the probability of positive secrecy over flat Nakagami-m fading channels.The second, we analyze the impact of antenna correlation on secrecy performance of single-input multiple-output(SIMO) wireless wiretap channels where receiver and eavesdropper employ MRC. We investigate the secrecy performance of MIMO wiretap channels with antenna correlation, where transmitter employs bestTAS while receiver and eavesdropper employ MRC, we present new closed-form expressions for the exact secrecy outage probability and the probability of positive secrecy. To obtain further insights, we also derive the asymptotic secrecy outage probability expression.The third, we investigate the secrecy performance of MIMO wiretap channels with antenna correlation, where transmitter employs general-order TAS while receiver and eavesdropper employ MRC. We derive new closed-form expressions for the exact secrecy outage probability, the probability of positive secrecy and the asymptotic secrecy outage probability expressions.