Secure Resource Allocation For Full-duplex Relay Networks

Communication capacity and security are the two of the most important aspects in the area of wireless communication.With the ability to improve system throughput and expand coverage,relay has attracted more and more interests.As for security,physical layer security(PLS)has been considered as a promising safety technique because its security can be verified in theory.Consequently,secure relay system is an interesting area that deserves to research on.Given that with the aid of the technique of full-duplex,both the throughput and the security of a secure relay system can be improved,we will focus on the secure performance as well as secure resource allocation schemes of full-duplex(FD)relay secure system.The contents of this dissertation are listed as follows.Firstly,the single antenna full-duplex secure relay networks with multiple source-destination pairs and multiple relay sub-nodes are considered.we try to find out how to allocate the secure re-sources properly to maximize the achievable secure rate.For this purpose,a single FD secure relay link with AF/DF strategy and artificial noise(AN)technique is studied firstly while the achievable secure rate of such an link is derived.Then,the problem of maximization of the system secure rate is formulated as a mixed-integer nonlinear programming(MINLP)problem,which can further be divided into two equivalent issues,the power allocation problem and the relay sub-nodes selection problem.The former is solved by particle swarm optimization(PSO)algorithm while the latter is transformed to a maximum weighted bipartite matching(MWBM)problem adopting Hungarian algorithm as resolution.Simulation results show that the combination of AN and FD relays can bring significant throughput improvement when the self-interference is well suppressed.What is more,it is shown the proposed resource allocation scheme is superior to other schemes.Secondly,the secure resource allocation problem of multiple input multiple output multi-antenna eavesdropper(MIMOME)FD relay system,is studied.We focus on the secure performance of the system with only statistical information of the wiretap channel.To solve this problem,the AN based secure communication scheme is proposed first and the closed-form expression of the achievable secure rate is derived.Then we propose the PSO-differential evolution(PSO-DE)based power allocation scheme for maximizing the achievable secure rate of the system.Furthermore,we propose two simplified power allocation schemes basing on the traditional power allocation algorithm.Simulation results show that the simplified schemes have the same performance as the PSO-DE scheme.Besides,the proposed scheme as well as the power allocation algorithm is proved to outperform several other half-duplex schemes.