Cooperative resource allocation in cognitive wireless powered communication networks with energy accumulation and deadline requirements

This study investigates a multi-carrier cognitive wireless powered communication network (CW-PCN) with a wirelessly powered primary user (PU). A two-stage cooperative protocol between the PU and the secondary user (SU) is adopted so that the PU can harvest energy from the SU while the SU gains transmission opportunities. It is assumed that the energy harvested by the PU can be accumulated for future usage, and the quality of service of the PU is guaranteed by satisfying the required minimum number of data bits for a given deadline. Herein, we maximize the SU rate by considering the time allocation, subcarrier allocation, and power allocation in both an offline setting (in which the future channel gains are known a priori) and an online setting (in which only the current channel gains are known). In the offline and online schemes, the maximization problem is solved using the block-coordinate descent method and the Lagrange duality method. The effectiveness of the proposed schemes is evaluated and verified via simulation experiments against benchmark schemes.