This paper considers a wireless-powered amplify-and-forward relay network with a large number of relays. Each relay node is equipped with a single antenna and harvests energy from its received signal with a power splitter. With the harvested power, each relay node forwards the residual received signal to the destination node with distributed beamforming. We investigate the impact of the power splitting ratio and the number of the relays on the system performance, and derive a closed-form expression for the asymptotic signal-to-noise ratio (SNR) when the number of relays goes large. Numerical results are presented to demonstrate the performance of the proposed scheme.
In this paper, we propose a low-complexity differential transmission scheme for a two-way relay network (TWRN) with two sources and one relay node, where each source is equipped with a single antenna, while the relay node is equipped with a large number of antennas. In the proposed scheme, no channel state information (CSI) is required at each source node for signal detection. It is shown that as the number of relay antennas becomes large, the received signal at each source node includes the desired signal only. Numerical results are presented to demonstrate the bit-to-error rate (BER) performance of the proposed scheme.