Selecting Multiple Transmit Antennas in MIMO System for Secrecy Capacity Enhancement

Due to the boundedness of traditional antenna selection scheme in enhancing secrecy security, we propose an antenna selection scheme in MIMO system which selects multi-antennas considering the fact that the eavesdroppers' channel state information (CSI) is unknown at the transmitter. We assume that the receiver and the eavesdropper combine the received signals employing the maximal ratio combining (MRC). Then we allocate transmit power of selected antennas using water-filling algorithm and analyze the secrecy capacity. The proposed scheme enhances the secrecy capacity visibly compare with the antenna selection scheme which selects only one antenna at the transmitter.(1)