The optimal power allocation for security in multicarrier relay power line communication

The physical layer security in broadband power line communications (PLCs) is considered to find the optimal power allocation that maximizes the secrecy rate in two-hop relaying multicarrier systems. In two-hop relaying systems, the optimal transmission scheme of each subcarrier is the one of the followings: No transmission, Direct transmission and Relay transmission. There are also five cases classified according to channel states between PLC nodes. In three cases, the optimal scheme is determined uniquely. In other two cases, the optimal scheme turns out to depend on the transmit power of the subcarrier. This increases computational complexity highly such that finding the optimal power allocation is impractical. In order to resolve this problem, we suggest the suboptimal power allocation and evaluate its performance in PLC network. The performance is compared to the other schemes such as the uniform power allocation and non-cooperative schemes.