隨著網路技術發展快速和行動裝置的普及，人們對於網路的需求日漸擴大，伴隨而來的是資料量需求大幅增加，以致於我們必須不斷發展新技術，甚至結合舊技術來達到所需的服務品質，而近年來5G網路研究中，非正交多重存取(Non-Orthogonal Multiple Access, NOMA)技術具有相當大的重要性，我們可以將多個使用者在功率域上疊加編碼傳輸，每位使用者能夠利用最大的頻寬，並且在接收端使用串行干擾消除法(Successive interference cancellation, SIC) 逐一解碼訊號並消除部分干擾，達到提升服務品質的目的。本文研究背景架構在異質性網路，藉由跨層細胞間的多點協調傳輸，結合非正交多重接取技術(NOMA)，探討系統吞吐量的最佳化，並且與合作式通訊系統及傳統系統作比較分析。本論文所建立的網路系統原始模型為非線性規劃問題，將藉由piecewise-RLT及對數項的數學簡化來進行線性放鬆，並且利用CPLEX之分枝切割法(Branch and cut)求得整個系統的最佳解。

As the network technology advance and the popularity of the smart mobile device, demands for the internet are rapidly increasing. Along with the sharp growth of data volume, we have to constantly evolve new technology and even combine the inherent approaches to achieve the QoS. Non-Orthogonal Multiple Access(NOMA) is crucial in recent research of the fifth-generation mobile networks. At the transmitter, we perform superposition coding on power-domain such that the maximum bandwidth can be used for each user, and with the interference-cancellation technique, we can also improve the quality of communication. In this paper, we combine NOMA with the cross-tier coordinated multipoint transmission(CoMP) based on heterogeneous cellular networks in order to explore the optimization of sum-throughput. The original model established in this paper is a nonlinear programming problem. After converting the model into a mixed-integer linear programming problem with the piecewise-RLT method and the mathematical simplification of logarithm terms, we can finally obtain the optimal solution of the system by using the branch and cut algorithm of CPLEX.

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