Research On The Secure Transmit Design In Wireless Information And Power Transfer Systems

Currently, with the rapid development of high-speed wireless communication networks and new network architecture, the energy demand of wireless-constrained mobile terminal and other equipment is increasingly becoming a bottleneck restricting network quality of service. The emergence of wireless information and power transfer system provides a new way to achieve high energy efficiency and long lasting network communication. Meanwhile, due to the openness nature of wireless netork, the legal information is vulnerable to be wiretapped by malicious receivers. Therefore, in this paper, the secure transmit design is considered in wireless information and power transfer systems, including the following aspects:Firstly, the secure transmission scheme in MIMO wiretap channel with simultaneous wireless information and power transfer is considered. Assuming the channel state information is perfectly known at the transmitter, a secure transmission scheme aimed to maximize the achievable secrecy rate by jointly design the precoding matrix, artificial noise(AN) covariance matrix and power splitting ratio is proposed. Then, simulation results of the proposed design are provided to show the effectiveness.Secondly, the perfect channel state information may be difficult to available at the transmitter because of the existence of varying channel characteristics, quantization and estimation error. So, the secure transmit design based on the deterministic model is taken into account, which the channel state information is not perfectly known at the transmitter. Then, the robust secure transmit design to maximixe the worst-case achievable secrecy rate is proposed by using the S-Procedure and Taylor series expansion technology. Simulation results are also provided to verify the effectiveness of the proposed design.Finally, due to the fact that some information transmitter need to use the harvested energy from the RF signal to transmit their information, in this paper, the secure transmit design based on WPCN is studied. By analyzing the effect of slot allocation on the secure transmission of the system, the optimal resource allocation strategies aimed to mazimize the achievable secure rate is propsed by jointly optimize the slot allocation factor, energy precoding matrix and the information precoding matrix, and the effectiveness of our proposed method has validated though simulation results.