Information and Energy Cooperation in Overlay Energy Harvested MIMO Cognitive Radio Systems

• Main Authors: Ting-Ying Lin, 林廷穎
• Other Authors: Fan-Shuo Tseng
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/p6h3bc

碩士 === 國立中山大學 === 通訊工程研究所 === 106 === In overlay hierarchical cognitive radio (HCR) networks, the primary system (PS) and the secondary system (SS) can cooperate to exploit the spectrum resource more efficiently. In this paper, we propose a new HCR, in which an energy harvesting (EH) device is additionally deployed at the primary receiver(PR) such that the PS can not only share the spectrum resources, but also harvest energy, achieving a new simultaneous wireless information and power transfer (SWIPT) paradigm. In the considered structure, the secondary base station (SB) can help relay PS’s signals via an amplify-and-forward (AF) protocol, and a power splitting EH device is adopted at the PR. A cooperative strategy is proposed for maximizing the efficiency of the information and power transfer. We optimize two precoders at the SB (for the PS and SS, respectively) and the power splitting factor for the PR. Since the optimization problem is nonconvex, it poses a significant challenge. To facilitate the optimization process, a precoding structure is first proposed to reduce the number of parameters. The resultant optimization problem can then be equivalently solved using a semidefinite relaxation (SDR) approach. Numerical results show that the proposed strategy provides a promising improvement for information and energy cooperation, as compared with existing methods.