A Robust Beamforming Approach to Guarantee Instantaneous Secrecy Rate
Abstract: We consider a well-known beamforming approach that induces jamming signals to avoid eavesdropping from a transmitter equipped with an antenna array in this paper. With this beamforming, which is called masked beamforming, in order to guarantee a certain instantaneous secrecy rate, we formulate robust beamforming problems with a constraint that deals with the eavesdropper channel's uncertainty and find the solutions. Unlike a guaranteed ergodic secrecy rate, this guaranteed instantaneous secrecy rate allows us to use codes of short codewords for secure communications with masked beamforming over slowfading channels. In addition, since the optimal solutions are found in closed form, we do not need to resort to any convex optimization solvers.