Enhancing secure wireless multicasting using phase alignment relay precoding

This paper deals with the case of secure wireless multicasting through multiple-input multiple-output (MIMO) radio system in which two co-existing users communicate with two groups of receivers in the presence of multiple eavesdroppers. Calculation of the secrecy multicast capacity of each group shows the impact of co-channel interferences (CCI) on it. Application of zero-forcing (ZF) or selective precoding at a relay enhances the secrecy multicast capacity of each group where former one eliminates the total interferences whether the latter uses constructive interferences energy as source of additional energy while cancels the destructive ones. The goal of this paper to apply phase-alignment relay precoding (PARP) scheme to use both the constructive and destructive elements of the interference to improve the secrecy multicast capacity at each group without the need to increase the transmitted power. Our results show that exploiting free interference power, the performance of co-existing wireless multicasting can be improved without affecting the performance of each other.