Research On Physical Layer Security Techniques Based On Cooperative Jamming

Due to the broadcast nature of the wireless medium, communication over the wireless channel is often susceptible to eavesdropping by unauthorized receivers and, thus, the need of secure transmissions over these channels poses great challenges in system design. The physical layer security techniques based on cooperative jamming mainly uses the reciprocity and uniqueness of wireless channel, by sending the artificial noise, effectively interfering eavesdroppers, while not affecting the legitimate user, thereby improving system security.In this paper, an enhanced physical layer security communication scheme is proposed for the multiple antenna systems. The scheme employing transmit antenna selection and artificial noise,also Alamouti coding, improved diversity gain in legitimate channel with low complexity in the transmitter and receiver, and at the same time efficiently jammed the wiretap channel. Consequently it can increase the system secrecy capacity. It analyzes the system secrecy capacity and the impacts of the number of antennas and the power allocation between the information signal and artificial noise. Simulation results demonstrate that the proposed scheme can effectively enhance the physical layer security.For the secure transmission of correlated source, this article puts forward the corresponding cooperative jamming strategy on the basis of distributed source coding theory. During the transmission of correlated source, wherein a part of the source information can be transformed into syndrome by LDPC encoding, the other part as side information, the receivers can get the source information according to syndrome and side information. This paper studies the cooperative jamming strategies where artificial noise technology is adopted when transmitting side information and syndrome respectively, also analyzes the allocation of transmission power. Simulation results show that it can save energy and system resources by introducing artificial noise technology when transmitting side information, which may interfere eavesdropping nodes without affecting the performance of the destination node.