Institute of Electrical & Electronic Engineers
The authors propose and analyze Transmit Antenna Selection (TAS) to enhance physical layer security in a wiretap channel with multiple antennas at the transmitter, the receiver, and the eavesdropper. They consider the practical scenario of passive eavesdropping, where the transmitter does not have any Channel State Information (CSI) of the eavesdropper's channel. In the main channel between the transmitter and the receiver, they select a single antenna at the transmitter that maximizes the instantaneous Signal-to-Noise Ratio (SNR) at the receiver. At the receiver and the eavesdropper, they consider two combining techniques: Maximal Ratio combining (MRC) and selection Combining (SC).