請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/48920
標題: | 在多細胞多群組群播系統中之波束形成設計 Beamformer Design for Multicell Multigroup Multicast Systems |
作者: | Guan-Wen Hsu 許冠文 |
指導教授: | 蘇炫榮 |
關鍵字: | 群播廣播單頻網路,多媒體廣播/群播系統,協同多點傳輸,協同波束形成,聯合處理,凸優化,穩健波束形成, Multicast Broadcast Single Frequency Network (MBSFN),multimedia broadcast/multicast system (MBMS),coordinated multipoint transmission (CoMP),coordinated beamforming,joint processing (JP),convex optimization,robust beamforming., |
出版年 : | 2016 |
學位: | 博士 |
摘要: | 本論文旨在探討於群播廣播單頻網路(MBSFN)場景中,如何透過多天線之波束形成(Beamforming)技術,設計出一個能夠在同頻帶之中,滿足各個基地台的傳輸功率上限,同時能提供不同群組用戶接收不同群播內容的服務需求。在本論文的前半部分研究內容之中,我們旨在研究如何於多個合作式基地台(cooperating base station, BS)之中,透過幾種最佳化方法,例如:半正定規劃(semidefinite program)、分數規劃(fractional program)、凸函式差分規劃(difference of convex program),去解決多天線之聯合波束形成(joint beamforming)的問題。其中,聯合波束形成技術亦即定義在LTE技術規格之中的多點協同傳輸(coordinated multipoint transmission, CoMP)之聯合處理技術(Joint Processing)。於本論文的後半部分研究內容之中,我們考慮一個更具延伸性的系統環境,其中,每個接收用戶均可配有多根接收天線。在此系統環境的設定之下,本論文提出了一個基於下行與上行對耦架構(downlink-uplink duality)之啟發式演算法(heuristic algorithm)來解決多天線之聯合波束形成的問題。此外,本論文也考慮了更高維度秩(rank)的傳輸方法以增進頻寬使用效率,同時,也提供了穩健波束形成設計(robust beamforming design)的方法,降低來自於通道估測誤差上所造成的系統效能下降的情形。於最後的模擬結果之中,本文比較了所提出來的演算法與傳統MBSFN傳輸方法,以及文獻中所提及的未採取合作式的演算法效能。模擬結果顯示,本文所提出的演算法將能展現較高的訊號與干擾雜訊比(signal to interference plus noise ratio, SINR)。此外,本文中也提供了穩健式與非穩健式波束形成技術的模擬數據, 吾人可藉由比較功率消耗、系統穩定比例(feasibility ratio),以及接收到SINR的數據直方圖來完成論述。 This dissertation considers a beamforming design problem in the Multicast Broadcast Single Frequency Network (MBSFN) scenario with multiple multicast groups that provide different multicast services. In the first part of this work, we devise different kinds of optimization techniques such as semidefinite relaxation, fractional program and difference of convex (DC) program to solve the joint beamforming design among the cooperating base stations (BSs), which is also known as the joint processing (JP) scheme in coordinated multipoint transmission (CoMP) defined in the Long-Term Evolution-Advanced (LTE-A) system. In the second part, we consider a more general scenario that each user is equipped with multiple receiving antennas. Therein, we propose a heuristic algorithm based on the downlink-uplink (DL-UL) duality structure to resolve the joint beamforming problem. Throughout the work, per-cell power constraints are considered. In addition, we consider the design of higher rank transmission to increase the spectrum efficiency, and the design of robust beamforming to alleviate performance degradation caused by imperfect channel state information. In the simulation results, we demonstrate the potential of the proposed algorithms in terms of the maximized minimum signal to interference plus noise ratio (SINR), and compare the proposed methods with the traditional MBSFN transmission scheme and the existing non-cooperating multicast beamforming methods. The results show that the proposed methods indeed provide better performance. We also provide numerical results of the robust and non-robust beamforming schemes in terms of the power consumption, feasibility ratio, and the histogram of the normalized SINR to complete the discussion. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/48920 |
DOI: | 10.6342/NTU201603522 |
全文授權: | 有償授權 |
顯示於系所單位: | 電信工程學研究所 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-105-1.pdf 目前未授權公開取用 | 3.63 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。