Date Added: May 2012
In this paper, the authors investigate the secrecy rate of finite alphabet communications over Multiple-Input, Multiple-Output, Multiple-antenna Eavesdropper (MIMOME) systems. Traditional precoder designs at the transmitter for achieving secrecy capacity (maximum secrecy rate) for MIMOME systems are developed according to the assumption of Gaussian input signals. Such designs may risk substantial secrecy rate loss when Gaussian inputs are replaced by practical finite alphabet inputs. To address this issue, they propose a linear precoding design to directly maximize the secrecy rate for MIMOME systems under the constraint of finite alphabet input.