| 摘要: | 非正交多重接取已成為下世代5G行動通訊系統的熱門技術選項之一，目前已列入在5G標準制定後討論項目。在這個計畫中，我們探討在多載波、非正交多重接取機制下，具向上鏈結波束成形系統之使用者及資源配置問題的探討，期使系統容量最大化。此資源配置問題，包含使用者選擇、波束成形技術模式、功率配置、子載波配置等問題。因第五代行動通訊標準，正交分頻多工亦被採用為多載波傳輸技術，因此本計畫也採取正交分頻多工為多載波傳輸方式。 先前，我們在單載波環境，使用非正交多重接取及使用迫零波束成形系統環境下，已設計使用者選擇、與功率配置的方法，模擬結果顯示，此所設計方法比現有方法有更好的效能。然而跟最佳解比，仍有改進之空間。在第一年計畫執行期間，我們將利用先前我們針對向下鏈結所提方法，來進一步改善此向上鏈結演算法之效能。此部分完成後，我們將延伸應用於多載波系統之演算法。此外，針對向上鏈結之非正交多重接取使用者配對性質，使用者的到達方向角來作使用者選擇與配對分群也是另一種設計演算法著墨的方向。 在第二年計畫執行期間，在另一方面，先前我們已進行探討在非完美通道情況下，作資源配置下對系統效能的影響初步了解，我們會針對迫零、最小平均平方錯誤、方向角等所形成的波束成形方式，作效能比較與分析，與演算法設計。除最大化傳輸率問題考量外，具錯誤率與傳輸速率之服務品質為限制條件之問題形成，也將於計畫執行作此向上鏈結演算法設計考量, 此方式為較少為文獻中所探討。 ;Non-orthogonal multiple access (NOMA) is one of techniques for improving the spectral efficiency and system capacity in 5G. It becomes one of study items in the beyond 5G era. In this project, we will investigate resource allocation problems to maximize capacity for an uplink beamforming multicarrier NOMA system. The resource allocation problems include the user selection and pairing, power allocation, and subcarrier allocation issues. As in the 5G standard, OFDM is still considered for the multicarrier transmission and therefore, we also adopt OFDM as our multicarrier transmission method. Previously, we have developed a user selection and grouping algorithm for uplink beamforming NOMA systems. The related power control algorithm is also developed. The scenario is a single carrier system. The simulation results show the proposed method outperform the existing method. There is some gap and room to improve towards the optimal solution. In the first year of the project execution, we are going to improve the performance by utilizing the idea of the previous proposed algorithm for downlink beamforming NOMA systems. After that, the proposed refined algorithm will be extended for OFDM-based multicarrier systems in the project. Besides, based on the uplink beamforming NOMA property, the parameters of users’angles of arrival will be utilized for the user selection and grouping algorithm design. In the second year of the project execution, on the other hand, we have also study the effect of imperfect channel information by performing the resource alloation algorithms. Therefore, in the project, we are going to study the impact of the imperfect channel on the resource allocation algorithm design. Zero-forming, minimum mean squared error, and AOA-based beamforming methods will be considered. The above design approaches are based on the rate maximization problem formulation. The criterion of the quality of service (QoS) of the rate and error rate constrains will also be considered for the algorithm design of the uplink systems during the project execution, which is seldom considered in the literature. |
