Enhancing Physical Layer Security in an Extended Alamouti Space-Time Block Coding Systems

In this paper, a new method for enhancing the physical layer security of an extended Alamouti space-time coding systems is presented. In this method, the transmitted signals from each antenna are designed in such way to be related to the corresponding channel of the intended receiver, assuming that the transmitter has the knowledge of that channel. Furthermore, the transmitter uses artificial noise and more than two antennas to obtain an additional security. Theoretical mathematical formulas are derived for one-branch, two-branch, and artificial noise aided multi-branch scenarios. Simulation results show the ability of proposed method in enhancing physical layer security compared with other existing methods.