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| DC 欄位 | 值 | 語言 |
|---|---|---|
| dc.contributor.advisor | 魏宏宇(Hung-Yu Wei) | |
| dc.contributor.author | Chih-Hsuan Chen | en |
| dc.contributor.author | 陳志軒 | zh_TW |
| dc.date.accessioned | 2021-06-13T01:02:34Z | - |
| dc.date.available | 2013-10-21 | |
| dc.date.copyright | 2011-10-21 | |
| dc.date.issued | 2011 | |
| dc.date.submitted | 2011-09-09 | |
| dc.identifier.citation | [1] Q. H. Spencer, C. B. Peel, A. L. Swindlehurst, and M. Haardt, “An introduction to the multi-user mimo downlink,” IEEE Communications Magazine, vol. 42, no. 10,pp. 60 – 67, Oct. 2004.
[2] V. K. N. Lau and Y. K. R. Kwok, Channel-Adaptive Technologies and Cross-Layer Designs for Wireless Systems with Multiple Antennas. John Wiley and Sons, Inc.,2006. [3] H. Weingarten, Y. Steinberg, and S. Shamai, “The capacity region of the gaussian mimo broadcast channel,” in Proceedings. International Symposium on Information Theory (ISIT 2004), Jun. 2004, p. 174. [4] Q. H. Spencer, A. L. Swindlehurst, andM. Haardt, “Zero-forcing methods for downlink spatial multiplexing in multiuser mimo channels,” IEEE Transactions on Signal Processing, vol. 52, no. 2, pp. 461–471, Feb. 2004. [5] L. U. Choi and R. D. Murch, “A transmit preprocessing technique for multiuser mimo systems using a decomposition approach,” IEEE Transactions on Wireless Communications, vol. 3, no. 1, pp. 20–24, Jan. 2004. [6] C.Wang and R. D.Murch, “Optimal downlink multi-user mimo cross-layer scheduling using hol packet waiting time,” IEEE Transactions on Wireless Communications,vol. 5, no. 10, pp. 2856–2862, Oct. 2006. [7] Y. J. Choi, N. H. Lee, and S. Bahk, “Ieee 802.11 performance enhancement by mimo spatial multiplexing,” in IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, 2005., vol. 1, Sept. 2005, pp. 87–91. [8] J. Zhang, J. G. Andrews, and R. W. Heath, “Block diagonalization in the mimo broadcast channel with delayed csit,” in IEEE Global Telecommunications Conference (GLOBECOM 2009), Dec. 2009, pp. 1–6. [9] N. Ravindran and N. Jindal, “Limited feedback-based block diagonalization for the mimo broadcast channel,” IEEE Journal on Selected Areas in Communications,vol. 26, no. 8, pp. 1473–1482, Oct. 2008. [10] IEEE P802.11ac/D1.0, May 2011. [11] T. Tandai, H.Mori, andM. Takagi, “Cross-layer-optimized user grouping strategy in downlink multiuser mimo systems,” in IEEE 69th Vehicular Technology Conference (VTC Spring 2009), Apr. 2009, pp. 1–6. [12] J. Zhang, M. Kountouris, J. G. Andrews, and R. W. Heath, “Multi-mode transmission for the mimo broadcast channel with imperfect channel state information,” IEEE Transactions on Communications, vol. 59, no. 3, pp. 803 –814, Mar. 2011. [13] C. Zhong and L. Yang, “Cross-layer scheduling and dynamic resource allocation for downlink multiuser mimo systems with limited feedback,” in International Work- shop on Cross Layer Design (IWCLD’07), Sept. 2007, pp. 1–4. [14] D. Gesbert and M. S. Alouini, “How much feedback is multi-user diversity really worth?” in IEEE International Conference on Communications, vol. 1, Jun. 2004, pp. 234–238. [15] R. Stacey, “Dl mu-mimo ack protocol,” IEEE 802.11 (TGac), Tech. Rep. 09/1172r0,Nov. 2009. [16] S. McCanne, S. Floyd, K. Fall, K. Varadhan et al., “Network simulator ns-2,” 1997. [17] V. Erceg, “Tgn channel models,” IEEE 802.11 (TGn), Tech. Rep. 03/0940r4, May 2004. [18] Q. Chen, F. Schmidt-Eisenlohr, D. Jiang, M. Torrent-Moreno, L. Delgrossi, and H. Hartenstein, “Overhaul of ieee 802.11 modeling and simulation in ns-2,” in Proceedings of the 10th ACM Symposium on Modeling, analysis, and simulation of wireless and mobile systems (MSWiM ’07). ACM, 2007, pp. 159–168. [19] C. Y. Wang and H. Y. Wei, “Ieee 802.11n mac enhancement and performance evaluation,” Mobile Networks and Applications, vol. 14, no. 6, pp. 760–771, 2009. [20] C. Yin, G. Wen, and Z. Feng, “Simulation research of 802.11n channel model d in ns2,” in 3rd IEEE International Conference on Computer Science and Information Technology (ICCSIT 2010), 2010, vol. 7, Jul. 2010, pp. 530–533. [21] L. Schumacher, “Wlan mimo channel matlab program,” http://www.info.fundp.ac.be/∼lsc/Research/IEEE 80211 HTSG CMSC/distribution terms.html. [22] G. Breit, “Tgac channel model addendum document,” IEEE 802.11 (TGac), Tech.Rep. 09/0308r12, Mar. 2010. [23] A. P. Stephens, “Usage models,” IEEE 802.11 (TGn), Tech. Rep. 03/802r23, May 2004. [24] R. Jain, G. Babic, B. Nagendra, and C. C. Lam, Fairness, call establishment latency and other performance metrics,” ATM Forum, Tech. Rep. 96-1173, Aug. 1996. [25] R. de Vegt, “802.11ac usage model document,” IEEE 802.11 (TGac), Tech. Rep. 09/0161r2, Mar. 2009. | |
| dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/29184 | - |
| dc.description.abstract | 在802.11ac的標準中，下行多使用者多輸入多輸出是其中一個用來提昇系統吞吐量的主要技術。然而，目前下行多使用者多輸入多輸出在802.11ac 網路中的整體效能尚未被完整的研究過。在這篇論文裡，我們在NS-2平台上實做了802.11ac的模組。藉由模擬，我們發現下行多使用者多輸入多輸出 只適合操作在某些SNR的範圍內。除此之外，通道狀態信息的回覆延遲和負擔也會對下行多使用者多輸入多輸出的效能造成影響。在把這些因素考慮 進來以後，我們提出了兩個演算法來最佳化下行多使用者多輸入多輸出在802.11ac網路中的效能。第一個演算法是混合式通道探測演算法(HCS)，這個演算法在通道探測時將使用者做排程，並使用混合式的回報頻率來減低回覆的負擔。第二個是多使用者多輸入多輸出排程及傳輸的機制(MUST)，這個機制對傳輸的模式做選擇並且對使用者做分組。MUST將隊列的狀態信息、通道狀態和回覆信息的延遲一起考慮進來以增進系統的吞吐量。模擬的結果顯示了提出的演算法的有效性。 | zh_TW |
| dc.description.abstract | In 802.11ac standard, downlink multi-user MIMO (DL MU-MIMO) is one of the main technologies to enhance system throughput. However, the overall performance of DL MU-MIMO in 802.11ac networks is not yet investigated. In this paper, we implemented an 802.11ac module on NS-2 platform. By simulations, we found that DL MU-MIMO is only suitable to operate at a certain SNR range. Besides, the channel state information feedback delay and overhead can also have an impact on DL MU-MIMO performance. Considering these effects, we then propose two algorithms to optimize the performance of DL MU-MIMO in 802.11ac networks. The first algorithm is hybrid channel sounding algorithm (HCS), which schedules the users in the channel sounding process and uses hybrid feedback frequency to reduce feedback overhead. The second is the MU-MIMO scheduling and transmission (MUST) mechanism, which performs transmission mode selection and user grouping. MUST jointly considers the queue status information, channel conditions, and impact of feedback information delay to optimize the system throughput. Simulation results demonstrate the effectiveness of the proposed algorithms. | en |
| dc.description.provenance | Made available in DSpace on 2021-06-13T01:02:34Z (GMT). No. of bitstreams: 1 ntu-100-R98942041-1.pdf: 2193216 bytes, checksum: d488b0e5b8be4133dc871a5ddf62ca9b (MD5) Previous issue date: 2011 | en |
| dc.description.tableofcontents | Master Thesis Certification by Oral Defense Committee i
Chinese Abstract ii Abstract iii 1 Introduction 1 2 Related Work 4 3 IEEE 802.11ac background 6 3.1 IEEE 802.11ac DL MU-MIMO ACK protocol . . . . . . . . . . . . . . . 6 3.2 IEEE 802.11ac NDP sounding protocol . . . . . . . . . . . . . . . . . . 7 4 IEEE 802.11ac NS-2 module 9 4.1 PHY module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4.2 MAC module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2.1 Transmitter side . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.2.2 Receiver side . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.2.3 NDP sounding protocol . . . . . . . . . . . . . . . . . . . . . . 14 4.3 Radio propagation module . . . . . . . . . . . . . . . . . . . . . . . . . 16 5 Initial simulation results and observations 18 5.1 PHY capacity simulation . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.2 Optimal sounding interval simulation . . . . . . . . . . . . . . . . . . . . 20 5.3 Summary of simulation observations . . . . . . . . . . . . . . . . . . . . 23 6 Proposed algorithms: HCS and MUST 24 6.1 HCS algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 6.2 MUST mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 7 Simulation results and analysis 33 7.1 Channel sounding overhead evaluation . . . . . . . . . . . . . . . . . . . 33 7.2 Capacity adjustment function evaluation . . . . . . . . . . . . . . . . . . 35 7.3 Packet duration adjustment evaluation . . . . . . . . . . . . . . . . . . . 37 7.4 Overall performance evaluation . . . . . . . . . . . . . . . . . . . . . . . 38 7.4.1 A typical usage scenario . . . . . . . . . . . . . . . . . . . . . . 39 7.4.2 Randomized scenarios . . . . . . . . . . . . . . . . . . . . . . . 40 8 Conclusions 46 Bibliography 47 | |
| dc.language.iso | en | |
| dc.subject | 排程 | zh_TW |
| dc.subject | 跨階層設計 | zh_TW |
| dc.subject | 使用者分組 | zh_TW |
| dc.subject | 回覆設計 | zh_TW |
| dc.subject | 多使用者多輸入多輸出 | zh_TW |
| dc.subject | 802.11ac | zh_TW |
| dc.subject | MU-MIMO | en |
| dc.subject | feedback design | en |
| dc.subject | scheduling | en |
| dc.subject | user grouping | en |
| dc.subject | cross-layer design | en |
| dc.subject | 802.11ac | en |
| dc.title | IEEE 802.11ac 下行多使用者多輸入多輸出之跨階層設計 | zh_TW |
| dc.title | Cross-layer Design for IEEE 802.11ac Downlink Multi-user MIMO | en |
| dc.type | Thesis | |
| dc.date.schoolyear | 99-2 | |
| dc.description.degree | 碩士 | |
| dc.contributor.oralexamcommittee | 蘇炫榮(Hsuan-Jung Su),周俊廷(Chun-Ting Chou),林靖茹(Ching-Ju Lin) | |
| dc.subject.keyword | 多使用者多輸入多輸出,802.11ac,跨階層設計,使用者分組,排程,回覆設計, | zh_TW |
| dc.subject.keyword | MU-MIMO,802.11ac,cross-layer design,user grouping,scheduling,feedback design, | en |
| dc.relation.page | 49 | |
| dc.rights.note | 有償授權 | |
| dc.date.accepted | 2011-09-12 | |
| dc.contributor.author-college | 電機資訊學院 | zh_TW |
| dc.contributor.author-dept | 電信工程學研究所 | zh_TW |
| 顯示於系所單位： | 電信工程學研究所 | |
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| ntu-100-1.pdf 未授權公開取用 | 2.14 MB | Adobe PDF |
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