在本篇論文的研究探討中，我們研究了包括用戶選擇，子載波分配和功率分配的資源分配，用於具有基地台服務的下行多載波非正交多重接取系統 Non-Orthogonal Multiple Access (NOMA)。根據對每個子載波上所有用戶的通道分析，我們首先從資源分配中刪除那些未滿足特定偵測性能要求的用戶。接著，我們在子載波分配，用戶選擇和功率分配方面訂定最佳化問題，以及在功率，最小通道容量和signal-to-noise ratio（SNR）條件下最大化系統總容量，以保證每位用戶的偵測效能。為了解決這個問題，我們提出了一個結合用戶選擇和功率分配的方法最大化每個子載波上的用戶數量，並受制於各用戶的最小速率和子載波上的傳送SNR要求。此外，提出了用於結合用戶選擇，子載波分配和功率分配的演算法，使得可以透過向用戶分配最少數量的子載波來滿足用戶的最小速率要求。最後，在每個子載波的相同用戶的傳送SNR要求下，通過使用注水原理來進行所有子載波之間的功率重新分配，以進一步提高系統容量。電腦模擬結果表示，所提出的多載波NOMA傳輸方法比傳統的Orthogonal Frequency Division Multiple Access (OFDMA)提供了顯著的通道容量增益。

In this thesis, we investigate resource allocation, including user selection, subcarrier allocation, and power allocation, for a downlink multicarrier non-orthogonal multiple access (NOMA) system with a number of users served by a base station. According to an analysis of channel conditions of all users on each subcarrier, we first remove the users that fail to meet a specific detection performance requirement from resource allocation. Then, we formulate an optimization problem in terms of subcarrier allocation, user selection, and power allocation to maximize the system sum capacity under specific power, minimum rate, and transmit signal-to-noise (SNR) constraints to guarantee the detection performance for each user. To solve this problem, we apply a combined user selection and power allocation method developed recently to maximize the number of users on a subcarrier for NOMA transmission subject to each user’s minimum rate and transmit SNR requirements on the subcarrier. Moreover, a suboptimal algorithm is proposed for joint user selection, subcarrier allocation, and power allocation such that the total minimum rate requirement for a user can be satisfied by assigning the minimum number of subcarriers to the user. Finally, under the same user’s transmit SNR requirements on each subcarrier, power re-allocation among all subcarriers is performed by using the water-filling technique for further improvement in the system capacity. Computer simulation results show that the proposed multicarrier NOMA transmission scheme provides a significant capacity gain over the conventional orthogonal frequency division multiple access system.

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