Spectrum Utilization Improvement for Multi-Channel Cognitive Radio Networks with Energy Harvesting

Abstract

Motivated by the dilemma in the multi-channel spectrum sensing by the multi-antenna user, this paper focuses on the scheme of spectrum sensing and energy harvesting to coordinate the time scheduling and energy management in the cognitive radio networks (CRNs), where a secondary transmitter (ST) exploits spectrum holes to transmit data through multichannel. To improve spectrum utilization efficiency, we investigate how the ST selects channels for sensing based on the residual energy, and adjusts the time scheduling of energy harvesting and data transmission with respect to the sensing results. To address this problem, we propose an adaptive scheme concerning spectrum sensing, channel selection, energy harvesting, and data transmission (SCED) for the ST. Moreover, we formulate the optimization of spectrum utilization efficiency as a Markov decision process (MDP) problem, which is challenging due to the system space and action space. Furthermore, we solve the MDP problem by a proposed value iteration algorithm. Numerical results show that the spectrum utilization efficiency under the SCED scheme is better than that under other schemes.