On exploiting polarization for energy-harvesting enabled cooperative cognitive radio networking
Qinyu Zhang, Bin Qian Cao, Ye Wang, Naitong Zhang, Xiaodong Lin, Limin Sun · IEEE Wireless Communications · 2013
Radio spectrum underutilization and energy inefficiency become urgent bottleneck problems to the sustainable development of wireless technologies. The research philosophies of wireless communications have been shifted from balancing reliability-efficiency tradeoff in the link level to seeking spectrum-energy efficiency in the network level. Global spectrum-energy efficient designs attract significant attention to improving utilization and efficiency, wherein cognitive radio networks and energy scavenging related techniques are of particular interests. In this article, we first provide a systematic study on cooperative cognitive radio networking (CCRN), followed by the discussions on research issues and challenges in designing spectrum-energy complexity efficient CCRN. As an effort to shed light on addressing spectrum-energy inefficiency at a low complexity, a novel CCRN paradigm exploiting polarization and energy harvesting capabilities is elaborated. Specifically, we present a novel polarization and energy harvesting based framework for achieving size-cost effective CCRN. We introduce polarization signal processing to avoid interference between secondary users and primary users in cooperation. We propose a weighted sum spectrum efficiency based problem formulation and multi-timescale dynamic programming based energy/power allocation policy to evaluate the cooperation performance, subject to energy levels, power, and throughput constraints.