臺灣博碩士論文加值系統

在本篇論文中提出一個下行多載波和多重使用者的波束合成(Beamforming)技術並以非正交多重接取(NOMA)為基礎的方式。我們在此系統中可以利用使用者分組的差異以及功率分配來提升系統的總容量。在使用者分組的方法中，我們藉由相關性將兩個使用者劃分成一組。此外單一的波束合成向量可以提供給同組內的兩個使用者共享，因此相較於正交多重接取(OMA)而言，此系統可以支援更多的使用者。在同一個組別中，其中一個使用者稱為強使用者則另一個稱為弱使用者。為了改善系統的總容量，我們需要解決來自其他波束合成的干擾以及在相同波束合成中但來自不同使用者的干擾。連續干擾消除技術(SIC)是一種用來消除來自弱使用者干擾的技術。我們在本系統中使用的是多載波而非單載波，此外多載波可以改善頻寬效率。我們在每個使用者間提出了一種子載波配置方案，而此方案可用來增強波束合成與非正交多重接取系統的總容量。在本系統下，我們確保了全部的子載波皆能指派給強使用者，但不可能單獨指派給弱使用者。我們也討論到在不同子載波和不同的總功率情況下，該如何分配資源給強使用者與弱使用者。本篇的模擬結果驗證了我們所提出的在波束合成與非正交多重接取系統下的子載波配置方案和在常態性的波束合成與非正交多重接取系統的比較下，本篇提出的子載波配置方案將會改善系統總容量。

In this paper, we propose a non-orthogonal multiple access systems based on multiuser beamforming (BF-NOMA) and multicarrier systems on downlink. In BF-NOMA systems, we can use a method for user grouping and power allocation to enhance the system sum capacity. The user grouping method, we divided two users into a group with correlation. In addition, a single BF vector is be shared by two users in a group, so that we can support more users than OMA sysyem. One user is strong user and the other is weak user in the same group. We need to solve the interference from the other beam and other user in the same beam in order to improve the system sum capacity. Successive interference cancellation is a technique to eliminate the interference derived from the weak user. In this system, we use multi-carrier instead of single-carrier and it can improve bandwidth efficiency. We proposed a subcarrier allocation scheme between each user, so that enhance the sum capacity in BF-NOMA systems. We ensure that all assigned subcarriers transmit data to the strong user in the system, but it is not possible that the subcarrier is assigned to the weak user individually. We discuss how the strong and weak users do resource allocation under conditions of different subcarriers and sum rate. The simulation results verify that the proposed subcarrier allocation scheme in BF-NOMA improves the sum capacity, compared to the conventional BF-NOMA.

Contents
論文摘要 iv
Abstract vi
List of Figure xi
List of Tables xi
Chapter1. Introduction - 1 -
1.1. Non-orthogonal Multiple Access - 1 -
1.2. Multiple-Input multiple-output - 2 -
1.3. Zero-Forcing Beamforming - 2 -
1.4. Organization - 3 -
1.5. List of Abbreviations - 4 -
1.6. Notation - 5 -
Chapter2. System Model and Problem Formulation - 6 -
2.1. Non-Orthogonal Multiple Access System - 6 -
2.2. Problem Formulation - 12 -
Chapter3. User Grouping and Resource Allocation Scheme - 13 -
3.1. Propose User Grouping Scheme - 13 -
3.2. Power allocation - 16 -
3.3. Propose Subcarrier Allocation Scheme - 17 -
Chapter4. Simulation Results - 20 -
4.1. Simulation model - 20 -
4.2. Performance of NOMA resource allocation - 20 -
Chapter5. Computation Complexity - 23 -
Chapter6. Conclusion - 24 -
Reference - 25 -

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