Sum-Rate Maximization of Uplink Rate Splitting Multiple Access (RSMA) Communication
Sum-Rate Maximization of Uplink Rate Splitting Multiple Access (RSMA) Communication
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DOI：
10.1109/tmc.2020.3037374
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发表时间：
2022-07
影响因子：
7.9
通讯作者：
Zhaohui Yang;Mingzhe Chen;W. Saad;W. Xu;M. Shikh-Bahaei
中科院分区：
文献类型：
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作者：
Zhaohui Yang;Mingzhe Chen;W. Saad;W. Xu;M. Shikh-Bahaei
研究了上行速率分割多址(RSMA)通信中最大化无线用户和速率的问题。在所考虑的模型中，打算给单个用户的消息被分成具有独立发射功率的两个子消息，并且基站(BS)使用连续解码技术来解码所接收的消息。为了最大化每个用户的传输速率，用户必须调整其传输功率，并且BS必须确定从用户传输到BS的消息的解码顺序。通过调整用户的发射功率和基站的译码顺序，将该问题描述为一个具有比例速率约束的和速率最大化问题。然而，由于优化问题中的译码顺序变量是离散的，因此可以将原始的具有发射功率和译码顺序变量的最大化问题转化为仅具有速率分裂变量的问题。然后，确定每个用户的最优速率分割。在给定每个用户的最佳速率分割和译码顺序的情况下，计算每个用户的最佳发射功率。然后，通过穷举搜索法确定最优译码顺序。为了进一步降低RSMA中用于和速率最大化的优化算法的复杂度，提出了一种基于用户配对的算法，该算法允许两个用户在每对中使用RSMA，并使不同对中的用户能够被分配到正交频率。作为比较，对于非正交多址(NOMA)、频分多址(FDMA)和时分多址(TDMA)，得到了具有比例速率约束的最优和速率最大化解。仿真结果表明，与NOMA、FDMA和TDMA相比，RSMA可以获得高达10.0%、22.2%和81.2%的和速率增益。
In this paper, the problem of maximizing the wireless users’ sum-rate for uplink rate splitting multiple access (RSMA) communications is studied. In the considered model, the message intended for a single user is split into two sub-messages with separate transmit power and the base station (BS) uses a successive decoding technique to decode the received messages. To maximize each user’s transmission rate, the users must adjust their transmit power and the BS must determine the decoding order of the messages transmitted from the users to the BS. This problem is formulated as a sum-rate maximization problem with proportional rate constraints by adjusting the users’ transmit power and the BS’s decoding order. However, since the decoding order variable in the optimization problem is discrete, the original maximization problem with transmit power and decoding order variables can be transformed into a problem with only the rate splitting variable. Then, the optimal rate splitting of each user is determined. Given the optimal rate splitting of each user and a decoding order, the optimal transmit power of each user is calculated. Next, the optimal decoding order is determined by an exhaustive search method. To further reduce the complexity of the optimization algorithm used for sum-rate maximization in RSMA, a user pairing based algorithm is introduced, which enables two users to use RSMA in each pair and also enables the users in different pairs to be allocated with orthogonal frequency. For comparisons, the optimal sum-rate maximizing solutions with proportional rate constraints are obtained for non-orthogonal multiple access (NOMA), frequency division multiple access (FDMA), and time division multiple access (TDMA). Simulation results show that RSMA can achieve up to 10.0, 22.2, and 81.2 percent gains in terms of sum-rate compared to NOMA, FDMA, and TDMA.