Open AccessUplink NOMA transmissions in a cooperative relay network based on statistical channel state information
Author(s) -
AbdelRazeq Sharief,
Zhou Shengli,
Bansal Rajeev,
Zhao Ming
Publication year - 2019
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2018.5372
Subject(s) - noma , telecommunications link , computer science , relay , rayleigh fading , single antenna interference cancellation , channel state information , computer network , base station , ergodic theory , fading , cellular network , decoding methods , multipath propagation , channel (broadcasting) , wireless , telecommunications , power (physics) , mathematics , physics , quantum mechanics , mathematical analysis
Non‐orthogonal multiple access (NOMA) has recently attracted a lot of attention as a promising multiple access technology to be used in the fifth generation (5G) cellular networks. In this study, the authors investigate uplink NOMA transmissions in a cooperative cellular network in the presence of frequency selective multipath fading channels. Specifically, two users communicate with the base station simultaneously with existence of a half‐duplex relay employing the decode‐and‐forward scheme to assist the far user. At the transmitting nodes, the power allocation factors are decided based on the statistical channel state information (CSI) rather than perfect CSI, while at the receiving nodes, the decoding order between the users is pre‐specified and the effect of imperfect successive interference cancellation implementation is taken into account. Under Rayleigh fading channels, the authors derive the exact ergodic rate for the near user and the upper bound of the ergodic rate for the far user, and present an ad‐hoc approach to determine the power allocation factors when the target data rates are given. Simulation results show that NOMA consistently outperforms orthogonal multiple access, however, the performance of uplink NOMA depends heavily on the proper choices of the power allocation factors and the relay location.