Downlink Sum-Rate Maximization for Rate Splitting Multiple Access (RSMA)
Downlink Sum-Rate Maximization for Rate Splitting Multiple Access (RSMA)
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速率分割多址 (RSMA) 的下行链路总速率最大化
DOI：
10.1109/icc40277.2020.9149417
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Shikh-Bahaei, Mohammad
中科院分区：
文献类型：
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作者：
Yang, Zhaohui;Chen, Mingzhe;Saad, Walid;Shikh-Bahaei, Mohammad
研究了采用下行链路速率分割多址接入（RSMA）的无线网络中的和速率最大化问题。在所考虑的模型中，每个基站（BS）将必须发送给其用户的消息划分为“私有”部分和“公共”部分。这里，公共消息是所有用户想要接收的消息，而私人消息是仅专用于特定用户的消息。RSMA机制使得BS能够调整公共消息和私有消息的划分，以便通过解码和将干扰视为噪声来控制干扰，从而优化用户的数据速率。为了最大化用户的和速率，网络可以确定公共消息的速率分配以满足速率需求，并且调整私有消息的发射功率以减小干扰。这个问题被制定为一个优化问题，其目标是最大化所有用户的总速率。为了解决这个非凸最大化问题，用于发送私人消息到用户的最佳功率首先获得在封闭的形式为一个给定的速率分配和公共消息功率。基于最优的私有消息发送功率，然后在固定的公共消息发送功率下导出最优速率分配。随后，提出了一种一维搜索算法来获得公共消息发送功率的最优解。仿真结果表明，与非正交多址（NOMA）和正交频分多址（OFDMA）相比，RSMA可以实现高达19.6%和23.5%的数据速率增益。
In this paper, the sum-rate maximization problem is studied for wireless networks that use downlink rate splitting multiple access (RSMA). In the considered model, each base station (BS) divides the messages that must be transmitted to its users into a “private” part and a “common” part. Here, the common message is a message that all users want to receive and the private message is a message that is dedicated to only a specific user. The RSMA mechanism enables a BS to adjust the split of common and private messages so as to control the interference by decoding and treating interference as noise and, thus optimizing the data rate of users. To maximize the users' sum-rate, the network can determine the rate allocation for the common message to meet the rate demand, and adjust the transmit power for the private message to reduce the interference. This problem is formulated as an optimization problem whose goal is to maximize the sum-rate of all users. To solve this nonconvex maximization problem, the optimal power used for transmitting the private message to the users is first obtained in closed form for a given rate allocation and common message power. Based on the optimal private message transmission power, the optimal rate allocation is then derived under a fixed common message transmission power. Subsequently, a one-dimensional search algorithm is proposed to obtain the optimal solution of common message transmission power. Simulation results show that the RSMA can achieve up to 19.6% and 23.5% gains in terms of data rate compared to non-orthogonal multiple access (NOMA) and orthogonal frequency-division multiple access (OFDMA), respectively.