Downlink Beamforming Design with Simultaneous Energy and Secure Information Transmission

In this paper, we study a downlink wireless network consisting of wireless powered communication (WPC) system and a simultaneously wireless information and power transfer (SWIPT) systems. The SWIPT system simultaneously serves one information receiver (IR) while transferring power to a wireless device (WD). The wireless powered system consists of the WD and its IR. Both systems operate on the same frequency band. The WD is therefore able to take advantage of the wireless energy transfer from the SWIPT basestation (BS), interference power from the BS due to transmission of signals to IRs and the recycled power for energy harvesting. We aim to minimize the total transmitted power of the SWIPT BS subject to the signal-to-interference-and-noise ratio (SINR) target at the information receivers. In order to preserve the secrecy of the information transmitted by BS to IRs on the BS, we introduce a set of constraints SINR less than one.