Genetic Algorithm for Power Allocation and Subcarrier Pairing in Multiuser Cooperative Cognitive Networks

• Main Authors: wei-hung Xue, 薛惟鴻
• Other Authors: Wen-Hsien Fang
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/hx73vx

碩士 === 國立臺灣科技大學 === 電子工程系 === 107 === Orthogonal frequency division multiplexing (OFDM) systems are a promising communication technique nowadays. Meanwhile, cooperative networks and multi-user environment are common transmission technique in which a distributed antenna array can be created to provide spatial diversity gains by relaying each others messages to the destination based on the channel state information. Also, cognitive radio (CR) can effectively improve the spectrum efficiency. This thesis presents an efficient algorithm for joint subcarrier pairing and power allocation in multi-user OFDM-based cognitive decode-and-forward (DF) relay network. We aim to maximize the sum rate of the CR users by effectively power allocation, subcarrier allocation, and user select under the individual power constrains. The source and the relay with the interference introduced to the primary user (PU) being kept below a tolerable range. Such a joint consideration become a mixed integer programming (MIP) problem. To resolve MIP problem, a novel genetic algorithm (GA) is addressed, which tackles all of these issues as a whole and free of extra assumptions made in previous works to simplify the problem. A new initialization is also addressed to achieve better performance. Simulation results show that the proposed method outperforms the state-of-the-art works.