Backhaul Pairing of Small Cells Using NonOrthogonal Multiple Access Wireless backhaul of outdoor small cells is a costeffective solution in a dense heterogeneous network as it reduces the need to provide a wired connection for each small cell access point to the core network. On the other hand, nonorthogonal multiple access (NOMA) has emerged as a promising technology to improve the spectral efficiency of a network. This paper investigates the impact of applying NOMA at the backhaul of small cells to enhance the spectral efficiency of the system. However, this requires a careful pairing of desired small cells to increase the system performance of NOMA. In this regard, a joint pairing and resource (bandwidth and power) allocation scheme for the backhaul of small cells is studied based on the load of the small cells. Furthermore, our performance evaluation shows that the proposed scheme outperforms the existing user pairing approaches in terms of achieving high spectral efficiency.

A New Green Prospective of Nonorthogonal Multiple Access (NOMA) for 5G Energy efficiency is a major concern in the emerging mobile cellular wireless networks since massive connectivity is to be expected with high energy requirements from the network operators. Nonorthogonal multiple access (NOMA) being the frontier multiple access scheme for 5G, there exists numerous research attempts on enhancing the energy efficiency of NOMA enabled wireless networks while maintaining its outstanding performance metrics such as high throughput, data rates and capacity maximized optimally.The concept of green NOMA is introduced in a generalized manner to identify the energy efficient NOMA schemes. These schemes will result in an optimal scenario in which the energy generated for communication is managed sustainably. Hence, the effect on the environment, economy, living beings, etc is minimized. The recent research developments are classified for a better understanding of areas which are lacking attention and needs further improvement. Also, the performance comparison of energy efficient, NOMA schemes against conventional NOMA is presented. Finally, challenges and emerging research trends, for energy efficient NOMA are discussed.