A Review of Power Domain Non-Orthogonal Multiple Access in 5G Networks

This paper highlights the fundamentals of the strong candidate Power Domain Non-Orthogonal Multiple Access (PD-NOMA) technique, and how it can best fit the requirements of fifth Generation (5G) in practical applications. PD-NOMA ensures flexibility in radio resource to improve user’s access performance. Multiple users share the same radio resources in PD-NOMA, and therefore better spectrum efficiency can be achieved. The practical system design aspects of PD-NOMA are considered in this paper by exploring different network scenarios. Optimal performances of PD-NOMA system can be obtained by suitable power allocation schemes, with reduce the computational complexity, and advanced user pairing strategy. Theoretical formulation and solutions are also explained prior to the concept of downlink PD-NOMA. Challenges and future research windows are discussed before conclusion of this paper

Split-enabled 350–630 Gb/s optical interconnect with direct detection NOMA-CAP and 7-core multi-core fiber

The ever-growing data traffic volume inside data centers caused by the popularization of cloud services and edge computing demands scalable and cost-efficient network infrastructures. With this premise, optical interconnects have recently gained more and more research attention as a key building block to ensure end-to-end energy efficient solutions, offering high throughput, low latency and reduced energy consumption compared to current networks based on active optical cables. An efficient way for performing such optical interconnects is to make use of multi-core fibers (MCFs), which enables the multiplexing of several spatial channels, each using a different core inside the same fiber cladding. Moreover, non-orthogonal multiple access combined with multi-band carrierless amplitude and phase modulation (NOMA-CAP) has been recently proposed as a potential candidate to increase the network capacity and an efficiency/flexibility resource management. In this paper, using direct detection we experimentally demonstrate the transmission of NOMA-CAP signals through a 2 km MCF with 7 spatial channels for high capacity optical interconnect applications. The results show negligible transmission penalty for different total aggregated traffics ranging from 350 Gb/s to 630 Gb/s.This work was supported in part by ALLIANCE (TEC2017-90034-C2-2-R) project co-funded by FEDER, the European Union’s Horizon 2020 research and innovation programme under grant agreement no780997 (plaCMOS), as well as MINECO FPI-BES-2015-074302Peer ReviewedPostprint (author's final draft