能量收集型高斯窃听信道安全速率的优化

针对无线网络存在安全威胁和能量受限的问题，该文研究了基于ST(Save-then-Transmit)协议的能量收集型高斯窃听信道的安全通信。首先，对系统安全速率最大化进行研究；其次，为进一步提高系统安全速率，给出了协作抗干扰方案，并讨论了该方案提高安全速率的充分必要条件，且提出了该方案下安全速率的迭代优化算法；最后，给出了一种复杂度低的单辅助端的选择方案。仿真结果表明，第1种优化方案明显提高了系统的安全速率；第2种协作抗干扰方案可进一步提高系统的安全速率且收敛速度较快；当原能量收集型高斯窃听信道不能进行安全通信时，协作抗干扰方案可在一定条件下实现安全传输。

Optimization of Secrecy Rate for Energy Harvesting Gaussian Wiretap Channel

To solve the problems of security threats and energy constrained in wireless networks, this paper studies secure communication of energy harvesting Gaussian wiretap channel based on Save-then-Transmit (ST) protocol. Firstly, the optimization of the system secrecy rate is studied. Next, to further improve the system secrecy rate, a Cooperative Jamming (CJ) scheme is given. Besides, the sufficient and necessary conditions for this scheme to achieve a higher secrecy rate are discussed. Then, an iterative optimization algorithm of the secrecy rate in this scheme is proposed. Finally, a low complexity selection scheme for single helper is given. Simulation results show that, the first optimization scheme obviously improves the system secrecy rate. The second cooperative jamming scheme can further enhance the system secrecy rate and has fast convergence rate. When the original energy harvesting Gaussian wiretap channel can not operate secure communication, the cooperative jamming scheme can achieve secure transmission under certain conditions.