Passive Radio-Frequency Energy Harvesting through Wireless Information Transmission

Passive radio-frequency (RF) energy harvesting collects the radiated energy from adjacent wireless information transmitters instead of using a dedicated wireless power source. In this paper, we investigate the scenario where a wireless transmitter communicates with its information receiver while intentionally focusing the radiated power to the RF energy harvesters. The wireless transceivers are equipped with multiple antennas, and each of the energy harvesters has one receive antenna. With an appropriate design of the transmit covariance matrix, the wireless transmitter transfers sufficient energy to the energy harvesters with a guarantee on the information rate to the communication receiver. When multiple RF energy harvesters are present, we address the trade-off between net energy harvesting rate and fairness with the dynamic of the energy harvesting network. Simulation results compare the algorithms and evaluate the performance of passive RF energy harvesting.