DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Han, Young-Nam | - |
dc.contributor.advisor | 한영남 | - |
dc.contributor.author | Han, Sang-Wook | - |
dc.contributor.author | 한상욱 | - |
dc.date.accessioned | 2011-12-28T02:45:12Z | - |
dc.date.available | 2011-12-28T02:45:12Z | - |
dc.date.issued | 2009 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=393138&flag=dissertation | - |
dc.identifier.uri | http://hdl.handle.net/10203/54630 | - |
dc.description | 학위논문(박사) - 한국정보통신대학교 : 공학부, 2009.2, [ viii, 90 p. ] | - |
dc.description.abstract | In wireless communication, many resource allocation and management problems are related with optimization problems. In this dissertation, we consider nonconvex power and rate optimization problems in wireless networks such as DS-CDMA, OFDMA, cognitive network using convex relaxation. This dissertation deals with efficient numerical solutions for nonconvex optimization problems for a class of optimization problems in wireless communications systems. By using convex relaxation, we can approximate the solution of nonconvex optimization problems in wireless communication systems. In this dissertation, we considers a distributed utility maximization power control scheme in up-link DS-CDMA systems. Maximizing a utility function is solved by Lagrangian dual decomposition. Numerical result shows that the proposed algorithm achieves around 95% of the optimal utility maximization with a modest computational burden. Also, we considers a sum-rate maximizing power allocation problem under Gaussian cognitive multiple-access channel (MAC) environment, where primary and secondary users may communicate under mutual interference. Formulating the problem as a standard nonconvex quadratically constrained quadratic problem (QCQP) provides a simple method to find a solution using semidefinite relaxation (SDR). Numerical results show that the solution achieves the similar performance of the exhaustive search, within polynomial time. In addition, we considers a novel auction algorithm for subchannel allocation using the difference of throughput among subchannels to allow users to compete through bidding in OFDMA system. The algorithm we proposed can achieve a competitive fair subchannel allocation through auction mechanism. Numerical result shows that the proposed algorithm has the similar performance with sum rate maximization and guarantees fairness by minimizing user``s potential throughput loss. | eng |
dc.language | eng | - |
dc.publisher | 한국정보통신대학교 | - |
dc.subject | 볼록 유연화 | - |
dc.subject | 최적화 | - |
dc.subject | 전력 전송률 제어 | - |
dc.subject | Optimization | - |
dc.subject | Power and Rate Control | - |
dc.subject | Convex Relaxation | - |
dc.title | Power and rate optimization in wireless networks using convex relaxation | - |
dc.type | Thesis(Ph.D) | - |
dc.identifier.CNRN | 393138/225023 | - |
dc.description.department | 한국정보통신대학교 : 공학부, | - |
dc.identifier.uid | 020035337 | - |
dc.contributor.localauthor | Han, Young-Nam | - |
dc.contributor.localauthor | 한영남 | - |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.