Artificial noise and LDPC code aided physical layer security enhancement

Low density parity check (LDPC) code and artificial noise are combined in wiretap channel to enhance the security in physical layer. Artificial noise is added at the transmitter using pre-coding. The artificial noise is designed that it spans a null space at the legitimate receiver but acts as random interference at the eavesdropper receiver. Moreover, a scrambling matrix is designed and then used in LDPC code to enhance the physical layer security. The outage probability of the wiretap channel is deduced, and then used in outage probability minimization. The performance of the proposed scheme is demonstrated with simulations.