TY - JOUR
T1 - Outage Constrained Power Efficient Design for Downlink NOMA Systems with Partial HARQ
AU - Xu, Yanqing
AU - Cai, Donghong
AU - Fang, Fang
AU - Ding, Zhiguo
AU - Shen, Chao
AU - Zhu, Gang
N1 - Funding Information:
Manuscript received January 17, 2020; revised March 25, 2020; accepted May 2, 2020. Date of publication May 7, 2020; date of current version August 14, 2020. The work of C. Shen was supported in part by the Fundamental Research Funds for the Central Universities under grant 2020JBM091, in part by the NSFC, China, under Grant 61871027 and Grant U1834210, in part by the State Key Laboratory of Rail Traffic Control and Safety under Grant RCS2019ZZ002, and in part by the National Key R&D Program of China under Grant 2018YFB1800804. This article was presented in part at the 2018 IEEE Global Communications Conference (GlobeCom), Abu Dahbi, United Arab Emirates. The associate editor coordinating the review of this article and approving it for publication was C. R. Murthy. (Corresponding author: Chao Shen.) Yanqing Xu, Chao Shen, and Gang Zhu are with the State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing 100044, China (e-mail: [email protected]; [email protected]; [email protected]).
Publisher Copyright:
© 2020 IEEE.
PY - 2020/8
Y1 - 2020/8
N2 - In this paper, we aim to design an adaptive power allocation scheme to minimize the average transmit power of a hybrid automatic repeat request with chase combining (HARQ-CC) enabled non-orthogonal multiple access (NOMA) system under strict outage constraints of users. Specifically, we assume that the base station only knows the statistical channel state information of the users. To achieve power efficient design and cope with the reliable transmissions of users, a partial HARQ-CC scheme is proposed. We first focus on the two-user case. To evaluate the performance of the two-user partial HARQ-CC enabled NOMA system, we first analyze the outage probability of each user. Then, an average power minimization problem is formulated. However, the attained expressions of the outage probabilities are nonconvex, and thus make the problem challenging to solve. Hence, we propose to use a successive convex approximation (SCA) based algorithm to solve the problem iteratively. Meanwhile, we prove that the proposed algorithm can converge to a Karush-Kuhn-Tucker point of the original problem. For more practical applications, we also investigate the partial HARQ-CC enabled transmissions in the multi-user scenario. The user pairing and power allocation problem is considered. With the aid of matching theory, a low complexity algorithm is presented to first handle the user pairing problem. Then the power allocation problem for each user pair is solved by the proposed SCA-based algorithm. Simulation results show the efficiency of the proposed transmission strategy and the near-optimality of the proposed algorithms.
AB - In this paper, we aim to design an adaptive power allocation scheme to minimize the average transmit power of a hybrid automatic repeat request with chase combining (HARQ-CC) enabled non-orthogonal multiple access (NOMA) system under strict outage constraints of users. Specifically, we assume that the base station only knows the statistical channel state information of the users. To achieve power efficient design and cope with the reliable transmissions of users, a partial HARQ-CC scheme is proposed. We first focus on the two-user case. To evaluate the performance of the two-user partial HARQ-CC enabled NOMA system, we first analyze the outage probability of each user. Then, an average power minimization problem is formulated. However, the attained expressions of the outage probabilities are nonconvex, and thus make the problem challenging to solve. Hence, we propose to use a successive convex approximation (SCA) based algorithm to solve the problem iteratively. Meanwhile, we prove that the proposed algorithm can converge to a Karush-Kuhn-Tucker point of the original problem. For more practical applications, we also investigate the partial HARQ-CC enabled transmissions in the multi-user scenario. The user pairing and power allocation problem is considered. With the aid of matching theory, a low complexity algorithm is presented to first handle the user pairing problem. Then the power allocation problem for each user pair is solved by the proposed SCA-based algorithm. Simulation results show the efficiency of the proposed transmission strategy and the near-optimality of the proposed algorithms.
KW - NOMA
KW - Partial HARQ-CC
KW - power allocation
KW - user pairing
UR - http://www.scopus.com/inward/record.url?scp=85090193878&partnerID=8YFLogxK
U2 - 10.1109/TCOMM.2020.2993080
DO - 10.1109/TCOMM.2020.2993080
M3 - Article
AN - SCOPUS:85090193878
SN - 0090-6778
VL - 68
SP - 5188
EP - 5201
JO - IEEE Transactions on Communications
JF - IEEE Transactions on Communications
IS - 8
M1 - 9089002
ER -