Harvest-Then-Transmit-Based TDMA Protocol with Statistical Channel State Information for Wireless Powered Sensor Networks

Wireless power transfer (WPT) is a promising solution for wireless sensor networks in IoT eras. However, due to the limitation of the spectrum, we need to address the research challenge of scheduling for both the power transfer and data transmission to maximize the spectrum efficiency. In this paper, we investigate harvest-then-transmit-based time division multiple access (TDMA) protocol with statistical channel state information. We show that the proposed protocol has the optimal time slot length to minimize the data transmission delay. Numerical results show that the proposed protocol achieves high spectrum efficiency and improve the battery charging ratio, compared with the existing harvest-then-transmit-based protocol.