Effects Of Action-dependent States And Channel Feedback On The Secrecy Capacities Of The Wiretap Channel With Noncausal State At The Transmitter

With the rapid development of communication technology,wireless communication has brought great convenience to our daily life,which is widely used in all aspects of society.But the broadcast characteristics of the wireless channel also make us face increasingly serious security issues,these security issues have made the research of wireless network physical layer security become a hot research field in recent years.The model of the state-dependent wiretap channel with the noncausal state at the transmitter,which plays an important role in the physical layer security of the wireless communication systems.This thesis studies the effects on the security capacities of the state-dependent wiretap channel with noncausal state at the transmitter by using channel feedback and action-dependent.In addition,a security coding and decoding scheme based on the Gaussian wiretap channel model is designed,and the simulation results show that our scheme has a good performance.Firstly,we investigated the action-dependent wiretap channel with noncausal state at the transmitter.Lower and upper bounds on the secrecy capacity of this model are proposed,and numerical results indicate that the actions on the state help to increase the achievable secrecy rate.Secondly,we proposed a new feedback scheme for the state-dependent wiretap channel with noncausal state at the transmitter and feedback,showing that our new scheme performs better than the already existing secret key-based feedback scheme and feedback enhance the achievable secrecy rate.The results are further explained via a Gaussian example.Then,we proposed two feedback coding schemes for the action-dependent wiretap channel with noncausal state at the transmitter and feedback.The first scheme follows from the already existing secret key-based feedback scheme for the wiretap channel,the second one follows from recently proposed hybrid feedback scheme for the wiretap channel.We show that for the action-dependent wiretap channel with noncausal state at the transmitter and feedback,the second feedback scheme performs better than the first one,both of the actions on the state and feedback can enhance the achievable secrecy rate.The capacity results are further explained via a Gaussian example.Finally,a security coding and decoding scheme based on the Gaussian wiretap channel is proposed and its security is verified by modeling and simulation.In this thesis,three wiretap channel models are studied.We show that both of action on the state and feedback improve the lower bound on the secrecy capacity of the state-dependent wiretap channel with the noncausal state at the transmitter.In addition,our proposed security coding and decoding scheme based on the Gaussian wiretap channels possesses good security.