  Ambient backscatter communications is an emerging paradigm and a key enabler
for pervasive connectivity of low-powered wireless devices. It is primarily
beneficial in the Internet of things (IoT) and the situations where computing
and connectivity capabilities expand to sensors and miniature devices that
exchange data on a low power budget. The premise of the ambient backscatter
communication is to build a network of devices capable of operating in a
battery-free manner by means of smart networking, radio frequency (RF) energy
harvesting and power management at the granularity of individual bits and
instructions. Due to this innovation in communication methods, it is essential
to investigate the performance of these devices under practical constraints. To
do so, this article formulates a model for wireless-powered ambient backscatter
devices and derives a closed-form expression of outage probability under
Rayleigh fading. Based on this expression, the article provides the
power-splitting factor that balances the tradeoff between energy harvesting and
achievable data rate. Our results also shed light on the complex interplay of a
power-splitting factor, amount of harvested energy, and the achievable data
rates.
