Title: Joint spectrum access and transmission power management for energy harvesting cognitive radio sensor networks

Authors: Fan Zhang; Tao Jing; Yan Huo; Kaiwei Jiang

Addresses: School of Electronics and Information Engineering, Beijing Jiaotong University, Beijing, BJ 10, China ' School of Electronics and Information Engineering, Beijing Jiaotong University, Beijing, BJ 10, China ' School of Electronics and Information Engineering, Beijing Jiaotong University, Beijing, BJ 10, China ' School of Electronics and Information Engineering, Beijing Jiaotong University, Beijing, BJ 10, China

Abstract: In this paper, we investigate the joint optimisation of spectrum access and the transmission power for an energy harvesting cognitive sensor node, which operates in time-slotted fashion with causal knowledge of channel conditions along with the energy harvesting states. Allowing for the sensing imperfection, we formulate this joint optimisation problem as an infinite-horizon discretetime Markov decision process (MDP), in which the cognitive sensor aims at maximising the long-term expected throughput. An optimal policy which specifies the spectrum access decision as well as the power level is proposed. It is indicated that the optimal long-term expected throughput is nondecreasing with the battery available energy. Moreover, we introduce a low-complexity policy and prove that the optimal low-complexity policy has a threshold structure with respect to the battery available energy. An efficient algorithm for deriving the optimal low-complexity policy is introduced. Finally, numerical results are presented to confirm the superiority of proposed policies.

Keywords: energy harvesting; cognitive radio; MDP; Markov decision process; sensor networks.

DOI: 10.1504/IJSNET.2018.092628

International Journal of Sensor Networks, 2018 Vol.27 No.2, pp.103 - 116

Received: 13 Jul 2017
Accepted: 25 Aug 2017
Published online: 26 Jun 2018 *

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