Experimental Evaluation on IEEE 802.15.4 Compatible Backscatter

Wireless communications for wireless devices require a significant power consumption for signal amplification. Such a significant power consumption may induce short lifetime of battery-operated wireless devices, especially, sensor devices and Internet of Things (IoT) devices. Backscatter communications have been proposed in recent years for ultra-low-power wireless communications, e.g., Wi-Fi. In this study, we propose and implement a novel backscatter communication scheme for sensor devices, i.e., IEEE 802.15.4-compatible backscatter. The proposed backscatter scheme consists of three devices: RF signal generator, backscatter transmitter, and standard IEEE 802.15.4 receiver. Specifically, the backscatter transmitter receives the RF signals with/without frequency hopping emitted from the RF signal generator and modulates the received signals into IEEE 802.15.4 packets by switching the impedance of the transmission antenna. Since the backscatter transmitter does not need signal amplification, instead, only needs to switch on/off state of the transmission antenna for packet transmissions, the power consumption of the proposed scheme is significantly lower than the conventional IEEE 802.15.4-based schemes. From the experimental evaluations, we demonstrated that the proposed backscatter scheme can realize IEEE 802.15.4 packet transmissions with low power at a certain angle and communication distance. In addition, we also clarified the frequency hopping at the RF signal generator can increase the number of the received packets since it may reduce the dead spots due to multi-path fading.