Date Added: Nov 2012
Secure communication in the Multi-User and Multi-Eavesdropper (MUME) scenario is considered in this paper. It has be shown that secrecy can be improved when the transmitter simultaneously transmits information signal to the legitimate receivers and artificial noise to confuse the eavesdroppers. Several processing schemes have been proposed to limit the Co-Channel Interference (CCI). The conventional method and the ZF beamforming method are simple but of little ideal performance. While the Block diagonalization (BD) method is of ideal performance but too complex. In this paper, the authors propose a new alternative approach based on maximizing the Signal-to-Leakage Ratio (SLR). Simulations demonstrates that the proposed SLR method can achieve compromise between the secrecy performance and complexity.