Energy Efficient Multiband Cooperative Spectrum Sensing for Heterogeneous Cognitive Industrial Wireless Sensor Networks

Abstract

Industrial wireless sensor networks (IWSNs) are facing more and more interference and coexistence problems as there is an explosive growth of wireless networks working in the unlicensed ISM band. To address these serious problems, we employ cognitive radio technology and formulate a novel cognitive IWSN with heterogeneous nodes, where cognitive nodes and sensor nodes separately perform spectrum sensing and data transmission. Correspondingly, we present a frame structure that allows both kinds of nodes to take up the whole frame for continuous spectrum sensing and successive data transmission, respectively. Then, a multiband cooperative spectrum sensing scheme (MB-CSS) is proposed for reliable and successive spectrum access. In this way, spectrum efficiency is enhanced while primary users are sufficiently protected. Furthermore, with the aim of minimizing energy cost, we optimize MB-CSS by solving mixed integer programming problems. Numerical results validate the availability of MB-CSS in heterogeneous cognitive IWNs, and demonstrate that the energy cost can be minimized under the condition that primary users are fully protected.