- The paper surveys the state-of-the-art integration of Non-Orthogonal Multiple Access (NOMA) with technologies like Massive MIMO, mmWave, cooperative/cognitive radio, energy harvesting, VLC, and MEC.
- It details how NOMA enhances spectral efficiency and user capacity when combined with Massive MIMO and provides advantages in cooperative/cognitive radio networks.
- The survey also explores physical layer security in NOMA, its integration with energy harvesting, VLC, and MEC, and discusses future research directions.
Overview of Non-Orthogonal Multiple Access (NOMA) and Emerging Technology Integration
The paper "Interplay Between NOMA and Other Emerging Technologies: A Survey" is a comprehensive survey examining the integration of Non-Orthogonal Multiple Access (NOMA) with various emerging wireless technologies. NOMA has gained significant attention as a promising multiple access scheme due to its potential to enhance spectral efficiency, user fairness, and connectivity in next-generation wireless networks. This paper reviews the state-of-the-art research on the synergy between NOMA and several advanced technologies, including Massive MIMO, mmWave communications, cooperative communications, cognitive radio, visible light communications, and mobile edge computing, among others.
NOMA and Massive MIMO
The integration of NOMA with Massive MIMO aims to address the limitations of orthogonal multiple access methods, particularly in scenarios with massive connectivity requirements. The paper details efforts to combine NOMA with sub-6 GHz and mmWave massive MIMO systems, emphasizing the benefits in spectral efficiency and user capacity. The analysis reveals that NOMA can outperform traditional OMA, particularly in overloaded systems where user numbers exceed the available resources, challenging the conventional wisdom of spatial multiplexing limits.
NOMA in Cooperative and Cognitive Communications
NOMA presents unique advantages in cooperative communication settings by enabling better resource sharing among users, improving throughput and fairness. The survey explores how NOMA, particularly with protocols like cooperative relaying, enhances the efficiency and reach of wireless networks. Similarly, in cognitive radio networks, NOMA is leveraged to access spectrum more dynamically and efficiently, providing new opportunities for spectral sharing and utilization, which are further explored through cognitive radio-inspired NOMA techniques.
Physical Layer Security in NOMA Networks
Security is critical in NOMA-based systems, particularly due to their non-orthogonal nature and the complexity added by multiple users. The survey investigates several physical layer security mechanisms applicable to NOMA, including artificial noise, beamforming, and antenna selection techniques. These methods aim to secure transmissions against eavesdroppers, both external and internal, reaffirming NOMA's viability in secure communications.
NOMA and Energy Harvesting Technologies
The integration of NOMA with energy harvesting paradigms like SWIPT and WPCN is discussed in-depth. These combinations allow NOMA systems to exploit harvested energy to power devices and relays efficiently, thereby supporting sustainable network growth and connectivity. The survey details how NOMA with energy harvesting not only improves energy efficiency but also allows for innovative applications in both uplink and downlink communications.
NOMA-VLC and Mobile Edge Computing (MEC)
In visible light communications (VLC), NOMA offers substantial enhancements in terms of bandwidth usage and user multiplexing capabilities. The survey highlights the use of NOMA in VLC systems to overcome limitations such as peak power constraints and improve user fairness.
In mobile edge computing, the paper emphasizes the capacity of NOMA to facilitate efficient offloading strategies, reducing latency and energy consumption in network operations. By integrating NOMA with MEC, the survey illustrates potential improvements in network efficiency, particularly in scenarios requiring rapid data processing and transfer at the network's edge.
Conclusions and Future Directions
The paper provides a detailed analysis of how NOMA can synergistically integrate with various emerging wireless technologies. It highlights the dual benefits of enhanced system performance and increased operational efficiency. The survey also identifies key research areas for further exploration, such as addressing non-ideal conditions like imperfect CSI, and developing advanced resource optimization strategies. Overall, the integration of NOMA with these emerging technologies represents a significant step towards the realization of efficient and robust next-generation wireless networks.