Secrecy Performance of Maximum Ratio Transmission with Correlated Main and Eavesdropper Channels

To investigate the effect of the correlation between main channel and eavesdropping channel on the secrecy performance of the wireless communication system. We proposed a multiple-input multiple-output wireless eavesdropping system, in which the base station transmits signals using maximum ratio transmit (MRT) technology, and both the legally receiving user and the eavesdropping user receive signals using the receiving antenna selection (RAS) technology. This scheme is called MRT/RAS. Under the premise that the main channel is correlated with the eavesdropping channel, we derived the mathematical expressions of secrecy outage probability and average secrecy capacity. Monte Carlo results and numerical analysis results are well matched, which proves the correctness of our analysis. By comparing the effect of SNR and correlation coefficient on system secrecy performance, we find that some conclusions: (1) when the main channel is in a low SNR, this correlation reduces the secrecy performance. However, in the case of medium to high SNR, this correlation improves secrecy performance. (2) This correlation is always detrimental to the average secrecy capacity of the system.