DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Sung, Dan Keun | - |
dc.contributor.advisor | 성단근 | - |
dc.contributor.author | Cha, Jiyoung | - |
dc.contributor.author | 차지영 | - |
dc.date.accessioned | 2018-05-23T19:37:23Z | - |
dc.date.available | 2018-05-23T19:37:23Z | - |
dc.date.issued | 2017 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=675813&flag=dissertation | en_US |
dc.identifier.uri | http://hdl.handle.net/10203/242015 | - |
dc.description | 학위논문(박사) - 한국과학기술원 : 전기및전자공학부, 2017.2,[v, 83 p. :] | - |
dc.description.abstract | The IEEE 802.11 wireless local area network (WLAN) standard has recently included multi-user multiple-input multiple-output (MU-MIMO) schemes both in uplink and downlink. Through the downlink MU-MIMO, an access point (AP) can simultaneously transmit multiple streams for different stations (STAs), while the uplink MU-MIMO enables multi-packet reception (MPR) with which the AP can successfully receive simultaneous transmissions from different STAs. In this dissertation, we focus on the medium access control (MAC) layer issues in carrier sense multiple access (CSMA) networks, e.g., WLANs with MU-MIMO considering physical layer behaviors. When each STA has a single antenna, we compare the system performance of downlink MU-MIMO with another downlink user multiplexing in time domain: a frame aggregation. The numerical results show a tradeoff of these schemes according to signal-to-noise ratio (SNR) region, and the differences of SNRs and packet length of multiplexed STAs. For uplink MU-MIMO, we discuss an unfairness problem in terms of channel access opportunity due to different frame error rates among STAs. We propose a fair channel access scheme and the performance evaluation results show that it significantly improves the fairness in terms of throughput as well as channel access opportunity. Besides, when each STA has multiple antennas, we propose a new backoff algorithm which adaptively selects the number of transmit antennas according to the queue state of backlogged STAs in uplink MPR-capable CSMA networks under an unsaturated traffic condition, in order to efficiently utilize the multiple transmit antennas. Moreover, to resolve a performance bottleneck of the proposed backoff algorithm in physical layer due to a per-STA power constraint, we propose a transmission scheme which opportunistically determines to transmit based on the channel condition. The performance evaluation results show that it efficiently resolve the performance bottleneck in physical layer while maintaining the benefit of using multiple transmit antennas in MAC layer. | - |
dc.language | eng | - |
dc.publisher | 한국과학기술원 | - |
dc.subject | CSMA | - |
dc.subject | WLAN | - |
dc.subject | MU-MIMO | - |
dc.subject | MAC protocol | - |
dc.subject | backoff algorithm | - |
dc.subject | 반송파 감지 다중접속 | - |
dc.subject | 무선랜 | - |
dc.subject | 다중사용자-다중입출력 | - |
dc.subject | 매체접근제어 프로토콜 | - |
dc.subject | 백오프 알고리즘 | - |
dc.title | CSMA-based random access networks with multi-user MIMO | - |
dc.title.alternative | 다중 사용자 MIMO를 지원하는 CSMA 기반의 랜덤 액세스 네트워크 | - |
dc.type | Thesis(Ph.D) | - |
dc.identifier.CNRN | 325007 | - |
dc.description.department | 한국과학기술원 :전기및전자공학부, | - |
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