Pre-Coder Design to Improve Secure Capacity in the MISO Wiretap Fading Channel with Spatial Correlations

In This paper, improving secure capacity using the appropriate pre-coder is investigated. Both main and wiretap channels assumed to be multiple-input single-output (MISO) wiretap channels. Also, the correlation between the Transmitting antennas is considered and broadcasting environment between the transmitter and each receiver is supposed to be Rayleigh fading. Secure capacity has been defined by the difference between the capacity of the main and the Eavesdropping channel. In the definition of secure capacity, channel correlation matrix is employed. Pre-coder is designed for the cases that the main receiver channel is superior and equal to the Eavesdropping channel. It is shown that that the proposed method has a superior performance regarding to secure capacity in comparison with similar pre-coding design algorithms.