TY - CHAP
T1 - Fair non-orthogonal multiple access communication systems with reconfigurable intelligent surface
AU - Xu, Yun
AU - Chen, Ming
AU - Yang, Zhaohui
AU - Liu, Yuanwei
AU - Long, Hui
AU - Shikh-Bahaei, Mohammad
PY - 2020/8
Y1 - 2020/8
N2 - Reconfigurable intelligent surface (RIS) is a promising solution to improve spectrum efficiency and promote cost- effectively wireless communication in the future. In this paper, RIS is deployed between a single-antenna base station (BS) and multiple single-antenna users to assist downlink non-orthogonal multiple access (NOMA) transmission. Considering the fairness among users, our goal is jointly optimizing the power allocation, decoding order, and the phase shifts to maximize the minimum user rate under total power constraint. To solve this minimum rate maximization problem, the optimal power allocation and the optimal fair rate are first revealed with a given phase shift vector. Then, the phase shift vector is optimized via maximizing the worst channel gain, which can determine the lower bound of the fair rate. The phase shift vector optimization problem is relaxed to a convex semidefinite program (SDP) and an efficient algorithm is proposed to obtain a rank-one solution. Simulation results show that our proposed algorithm can enhance the fair rate compared to the conventional scheme.
AB - Reconfigurable intelligent surface (RIS) is a promising solution to improve spectrum efficiency and promote cost- effectively wireless communication in the future. In this paper, RIS is deployed between a single-antenna base station (BS) and multiple single-antenna users to assist downlink non-orthogonal multiple access (NOMA) transmission. Considering the fairness among users, our goal is jointly optimizing the power allocation, decoding order, and the phase shifts to maximize the minimum user rate under total power constraint. To solve this minimum rate maximization problem, the optimal power allocation and the optimal fair rate are first revealed with a given phase shift vector. Then, the phase shift vector is optimized via maximizing the worst channel gain, which can determine the lower bound of the fair rate. The phase shift vector optimization problem is relaxed to a convex semidefinite program (SDP) and an efficient algorithm is proposed to obtain a rank-one solution. Simulation results show that our proposed algorithm can enhance the fair rate compared to the conventional scheme.
KW - Nonorthogonal multiple access
KW - Phase shift optimization
KW - Power allocation
KW - Reconfigurable intelligent surface
UR - http://www.scopus.com/inward/record.url?scp=85094136006&partnerID=8YFLogxK
U2 - 10.1109/PIMRC48278.2020.9217117
DO - 10.1109/PIMRC48278.2020.9217117
M3 - Conference paper
AN - SCOPUS:85094136006
T3 - IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC
BT - 2020 IEEE 31st Annual International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2020
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 31st IEEE Annual International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2020
Y2 - 31 August 2020 through 3 September 2020
ER -