Cooperative Resource Allocation in Cognitive Radio Networks With Wireless Powered Primary Users

This letter focuses on cooperative resource allocation in multi-carrier cognitive radio (CR) networks where the primary user (PU) is wirelessly powered by the energy harvested from the signals transmitted by the secondary user (SU) for its own information transfer. We adopt the two-stage harvest-then-transmit protocol, where the wireless power transfer for the PU is executed first and then the information transfer for the PU takes place. Specifically, two schemes, namely subcarrier sharing (SS) and subcarrier exclusivity, are considered for coordinating the information transfer of the PU and the SU in the second stage. The resource allocation problems to maximize the SU rate subject to the PU minimum rate constraint are investigated. It is shown that the SS scheme achieves higher SU rate than the SE scheme at the cost of higher computation time when the PU minimum rate constraint is stringent and the number of subcarriers is large.