Research On Transmission Scheduling And Proactive Eavesdropping Scheme Under Wireless Full-duplex Communication Scenario

In recent years,the next generation of wireless communication technology is facing the great challenges of spectrum resource shortage and communication information security with the explosive growth of mobile data traffic.Full-duplex(FD)technology has became one of the key technologies to meet these challenges because of its support equipment receiving and transmitting data simultaneously at the same frequency.In view of improving spectrum efficiency,this dissertation studies the problem of maximizing network utility by transmission scheduling in a full duplex wireless local area network(WLAN).Focus on enhancing surveillance performance,this dissertation studies the effective information surveillance problem in the full duplex proactive eavesdropping system combined with pilot contamination technology.The main results and contributions are summarized as follows:(1)Considering a WLAN based on full duplex access point(AP),where AP transmits date to one half-duplex user node while receives date from another half-duplex user node.However,the introduced uplink-downlink interference degrades network spectrum efficiency.To manage complicate interference in the network,a transmission scheduling scheme is proposed aiming at maximizing the total downlink user utility,In this scheme,the total of the downlink utility is maximized by optimizing the transmit power of AP and uplink users,access intensity and pairing relationship.Such an mixed integer nonlinear programming problem,we design an efficient transmission scheduling scheme based on continuous convex approximation and alternating iteration.Simulation results show the effectiveness of the proposed transmission scheduling scheme.(2)Considering a multiple input multiple output frequency division duplex wireless information surveillance scenario,the channel state information(CSI)obtained at legitimate monitor is imperfect,since the suspicious source with large-scale antenna array adopts limited pilot overhead to estimate channel.To improve the effective eavesdropping rate under imperfect CSI,a FD proactive eavesdropping scheme is proposed combining pilot contamination and jamming-assisted technology.In this scheme,the monitor sends deception pilot to control the channel estimation of the suspicious destination in the training phase.,and sends artificial noise to adjust the suspicious data rate in the data transmission phase.Moreover,the deception pilot sequence and transmit power of the monitor are designed to maximize the estimation error of the suspicious link.In addition,the transmit\receive beamforming of the monitor are designed to maximize the effective eavesdropping rate.The simulation results show that our proactive eavesdropping scheme is feasible,and the proposed joint optimization scheme is better than the two existing schemes in improving the surveillance performance.