Non-orthogonal multiple access (NOMA) is regarded as a promising technology to provide high spectral efficiency and support massive connectivity in 5G systems. In most existing NOMA user grouping approaches, users are grouped into disjoint groups, which may lead to a waste of power resources within each NOMA group. Motivated by this, in this paper we propose a novel generalized user grouping (GuG) concept for NOMA from an overlapping perspective, which allows each user to participate in multiple groups but subject to individual maximum power constraint. In order to achieve effective GuG and maximize the system sum rate, we formulate a joint power control and GuG optimization problem. Then, we address this problem by exploiting the overlapping coalition formation (OCF) game framework, and we further propose an OCF-based algorithm in which each user can be self-organized into a desirable overlapping coalition structure. Simulation results verify the efficiency of GuG in NOMA systems and indicate that compared with traditional NOMA user grouping schemes, our proposed OCF-based GuG NOMA scheme achieves significant performance gains in terms of system sum rate.
Bibliographical noteFunding Information:
This work was supported in part by the National Key Research and Development Project under Grant 2019YFB2102300 and Grant 2019YFB2102301, in part by the National Natural Science Foundation of China under Grant 61936014 and Grant 61901302, in part by the Scientific Research Project of Shanghai Science and Technology Committee under Grant 19511103302, in part by the Fundamental Research Funds for the Central Universities, in part by the National Science Foundation under Grant CPS-1932413 and Grant ECCS-1935915, and in part by the Natural Science Foundation of Shanghai under Grant 20ZR1462400. (Corresponding authors: Shengjie Zhao; Rongqing Zhang.)
© 1983-2012 IEEE.
- coalition formation
- generalized user grouping
- power control