Offloading data traffic via cognitive small cells with wireless powered user equipments

This paper investigates data traffic offloading by considering a third-party cognitive small cell with wireless powered user equipments (UEs) providing data traffic offloading service to a primary macrocell. The cognitive small cell is assumed to use remaining resources for its own purpose provided that the quality of service (QoS) of the primary macrocell is satisfied. It is assumed that the small cell UEs (SUEs) are wirelessly powered and can harvest energy from the RF signals transmitted by the macrocell UEs (MUEs) as well as the RF signals transmitted by the small cell BS (SBS). Under the assumption that the successive interference cancellation (SIC) decoder is available or not available at the SBS, iterative optimization-based data traffic offloading schemes are proposed to maximize the SUE sum rate provided that the required minimumMUE sum rate is satisfied. It is shown that the proposed data traffic offloading schemes are effective in improving the performance of the MUEs and providing transmission opportunities for the wireless powered SUEs.