TY - JOUR
T1 - Optimization of Rate Allocation and Power Control for Rate Splitting Multiple Access (RSMA)
AU - Yang, Zhaohui
AU - Chen, Mingzhe
AU - Saad, Walid
AU - Shikh-Bahaei, Mohammad
N1 - Funding Information:
Manuscript received September 28, 2020; revised February 4, 2021, April 30, 2021, and June 8, 2021; accepted June 9, 2021. Date of publication June 21, 2021; date of current version September 16, 2021. This work was supported in part by the U.S. National Science Foundation under Grant CNS-1836802, CNS-1909372, by the EPSRC SENSE Project under Grant EP/P003486/1 and by the Fundamental Research Funds for the Central Universities under Grant 2042021kf1030, and by the EPSRC IoSIRE Project under Grant EP/P022723/1. The associate editor coordinating the review of this article and approving it for publication was H. Zhang. This article was presented in part at the IEEE International Conference on Communications 2020 [1]. (Corresponding author: Mingzhe Chen.) Zhaohui Yang is with the Department of Electronic and Electrical Engineering, University College London, London WC1E 6BT, U.K., and also with the Centre for Telecommunications Research, Department of Engineering, King’s College London, London WC2R 2LS, U.K. (e-mail: [email protected]).
Publisher Copyright:
© 1972-2012 IEEE.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/9
Y1 - 2021/9
N2 - 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, the base station (BS) divides the messages that can be transmitted to its users into a 'private' part and a 'common' part. Here, the common message is a message that multiple 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 with a single-antenna BS, 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 transmit power, the optimal rate allocation is then derived under a fixed common message transmit power. Subsequently, an iterative algorithm is proposed to obtain a suboptimal solution of common message transmit power. To solve this nonconvex maximization problem with a multiple-antenna BS, a successive convex approximation method is utilized. Simulation results show that the RSMA can achieve up to 15.6% and 21.5% gains in terms of data rate compared to non-orthogonal multiple access (NOMA) and orthogonal frequency-division multiple access (OFDMA), respectively.
AB - 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, the base station (BS) divides the messages that can be transmitted to its users into a 'private' part and a 'common' part. Here, the common message is a message that multiple 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 with a single-antenna BS, 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 transmit power, the optimal rate allocation is then derived under a fixed common message transmit power. Subsequently, an iterative algorithm is proposed to obtain a suboptimal solution of common message transmit power. To solve this nonconvex maximization problem with a multiple-antenna BS, a successive convex approximation method is utilized. Simulation results show that the RSMA can achieve up to 15.6% and 21.5% gains in terms of data rate compared to non-orthogonal multiple access (NOMA) and orthogonal frequency-division multiple access (OFDMA), respectively.
KW - Downlink
KW - Interference
KW - MISO communication
KW - NOMA
KW - power control
KW - Power control
KW - rate allocation
KW - Rate splitting multiple access
KW - Resource management
KW - Silicon carbide
KW - sum-rate maximization
UR - http://www.scopus.com/inward/record.url?scp=85112435983&partnerID=8YFLogxK
U2 - 10.1109/TCOMM.2021.3091133
DO - 10.1109/TCOMM.2021.3091133
M3 - Article
AN - SCOPUS:85112435983
SN - 0090-6778
VL - 69
SP - 5988
EP - 6002
JO - IEEE TRANSACTIONS ON COMMUNICATIONS
JF - IEEE TRANSACTIONS ON COMMUNICATIONS
IS - 9
ER -