TY - JOUR
T1 - Impact of User Pairing on 5G Nonorthogonal Multiple-Access Downlink Transmissions
AU - Ding, Zhiguo
AU - Fan, Pingzhi
AU - Poor, H. Vincent
N1 - Funding Information:
The work of Z. Ding was supported by the Engineering and Physical Sciences Research Council of U.K. under Grant EP/L025272/1. The work of P. Fan was supported in part by the National Natural Science Foundation of China under Grant 61471302 and in part by the 111 Project of China under Grant 111-2-14. The work of H. V. Poor was supported by the U.S. National Science Foundation under Grant CNS-1456793 and Grant ECCS-1343210.
Publisher Copyright:
© 1967-2012 IEEE.
PY - 2016/8
Y1 - 2016/8
N2 - Nonorthogonal multiple access (NOMA) represents a paradigm shift from conventional orthogonal multiple-access (MA) concepts and has been recognized as one of the key enabling technologies for fifth-generation mobile networks. In this paper, the impact of user pairing on the performance of two NOMA systems, i.e., NOMA with fixed power allocation (F-NOMA) and cognitive-radio-inspired NOMA (CR-NOMA), is characterized. For F-NOMA, both analytical and numerical results are provided to demonstrate that F-NOMA can offer a larger sum rate than orthogonal MA, and the performance gain of F-NOMA over conventional MA can be further enlarged by selecting users whose channel conditions are more distinctive. For CR-NOMA, the quality of service (QoS) for users with poorer channel conditions can be guaranteed since the transmit power allocated to other users is constrained following the concept of cognitive radio networks. Because of this constraint, CR-NOMA exhibits a different behavior compared with F-NOMA. For example, for the user with the best channel condition, CR-NOMA prefers to pair it with the user with the second best channel condition, whereas the user with the worst channel condition is preferred by F-NOMA.
AB - Nonorthogonal multiple access (NOMA) represents a paradigm shift from conventional orthogonal multiple-access (MA) concepts and has been recognized as one of the key enabling technologies for fifth-generation mobile networks. In this paper, the impact of user pairing on the performance of two NOMA systems, i.e., NOMA with fixed power allocation (F-NOMA) and cognitive-radio-inspired NOMA (CR-NOMA), is characterized. For F-NOMA, both analytical and numerical results are provided to demonstrate that F-NOMA can offer a larger sum rate than orthogonal MA, and the performance gain of F-NOMA over conventional MA can be further enlarged by selecting users whose channel conditions are more distinctive. For CR-NOMA, the quality of service (QoS) for users with poorer channel conditions can be guaranteed since the transmit power allocated to other users is constrained following the concept of cognitive radio networks. Because of this constraint, CR-NOMA exhibits a different behavior compared with F-NOMA. For example, for the user with the best channel condition, CR-NOMA prefers to pair it with the user with the second best channel condition, whereas the user with the worst channel condition is preferred by F-NOMA.
KW - Cognitive radio
KW - nonorthogonal multiple access (NOMA)
KW - power allocation
KW - user pairing and outage probability
UR - http://www.scopus.com/inward/record.url?scp=84969985979&partnerID=8YFLogxK
U2 - 10.1109/TVT.2015.2480766
DO - 10.1109/TVT.2015.2480766
M3 - Article
AN - SCOPUS:84969985979
SN - 0018-9545
VL - 65
SP - 6010
EP - 6023
JO - IEEE Transactions on Vehicular Technology
JF - IEEE Transactions on Vehicular Technology
IS - 8
M1 - 7273963
ER -