Wireless Powered Large-Scale Multi-Antenna AF Relaying for Cooperative Jamming-Aided Secrecy

Abstract

This paper studies the secrecy transmission with the aid of a large-scale multi-antenna amplify-and-forward (AF) relay wireless powered by the source. Specifically, the wireless energy harvesting (WEH)-enabled relay devices a hybrid receiver architecture, in which the received power at each individual antenna is split for energy harvesting (EH) and information receiving (IR) in the first transmission phase; the aggregate of the total harvested power is further split for cooperative jamming (CJ) to confound the eavesdroppers, and AF using maximum ratio combining (MRC) and maximum ratio transmitting (MRT), respectively, at the relay in the second transmission phase. Assuming that the eavesdroppers in the proximity are distributed as Poisson point process (PPP), no channel state information (CSI) but the density of which is known to the relay, the ergodic secrecy rate (ESR) is used to characterize the secrecy performance. The optimum portion of power allocated for CJ is also derived to significantly improve on the ESR especially in the case of high eavesdroppers' density.