A Contract-Based Pricing Mechanism for Simultaneous Information and Energy Transfer

Abstract

Wireless energy harvesting, scavenging energy from ambient radio signals, has been recently viewed as a promising solution to extend the operation time of the various mobile devices. In this paper, we use a contract approach to study the power allocation and pricing issue for the simultaneous wireless information and power transfer (SWIPT) in a downlink cellular network, where a monopoly mobile network operator (MNO) gains revenue from providing both information and energy transfer for its subscribers. Each user decides his optimal power splitting ratio to harvest energy as much as possible when the required data rate can be satisfied. Specifically, the MNO will design and offer a set of contract items in the form of transmit power and the corresponding price. Then each user will choose the best contract item based on his private information (user's type). Furthermore, we first derive the necessary and sufficient condition to make the contract feasible, i.e., satisfying incentive compatibility (IC) and individual rationality (IR) constraints, and then we derive the optimal and feasible contract that maximizes the MNO's profit. Finally, the numerical results show that the MNO tends to exclude some users from enjoying wireless power transfer service to maximize its profit. And when the energy harvesting efficiency increases, the MNO will include more users to enjoy the power transfer.