MIMO Wiretap Channels: Secure Transmission Using Transmit Antenna Selection and Receive Generalized Selection Combining

We propose and analyze transmit antenna selection with receive generalized selection combining (TAS/GSC) for physical layer security enhancement in multiple-input multiple-output wiretap channels. In this protocol, a single antenna out of N_A antennas is selected at the transmitter and L_B antennas out of N_B antennas are combined at the legitimate receiver. We characterize the physical layer secrecy of TAS/GSC via our new closed-form expressions for the exact and the asymptotic secrecy outage probability. We demonstrate that the maximum secrecy outage diversity gain of N_A N_B is achieved.