Framework for MIMO cross-layer secure communication based on STBC

The wireless networks lack a physical boundary due to the broadcasting nature of wireless transmissions. The security has become a critical concern in the physical layer of wireless networks. Physical-layer security techniques are effective in resolving the boundary, efficiency and link reliability issues, but they can not be able to guarantee security with probability 1. In this work, we present a cross-layer security scheme for STBC system. By introducing a distort signal set the sender randomly flip-flops between the distort signal set and the orthogonal code set to confuse the attacker. The physical-layer security is enhanced as a result. In the proposed scheme the physical-layer may rely on upper-layer encryption techniques for security, which results in a cross-layer security scheme. Our approach can guarantee enhanced security with probability 1 in the wireless networks.