I. Introduction
A. Related Work and Existing Surveys
B. Paper Organization
II. Background
A. Power Domain NOMA
B. MISO, MIMO, and mMIMO Communications
C. Advanced Multi-antenna Architectures
D. mmWave and THz Communications
E. Coordinated Multi-Point (CoMP) Schemes
F. Cooperative Communications
G. Cognitive Radio Communications
H. Visible Light Communications (VLC)
I. Unmanned Aerial Vehicle (UAV) Assisted Communications
J. Other Enabling Technologies
K. Machine Learning
IV. Future Research Directions
A. MISO, MIMO, and mMIMO Communications
B. Advanced Multi-antenna Architectures
C. mmWave and THz Communications
D. CoMP-NOMA Communications Schemes
E. Cooperative NOMA Communications
F. Cognitive Radio NOMA Communications
G. VLC-NOMA
H. UAV-NOMA Assisted Communications
I. Other Enabling Technologies
J. Rate Optimization of NOMA-enabled Systems with Machine Learning
V. Conclusion