D2D NOMA Groupcast in 5G Heterogeneous Networks

In traditional 5G latency-driven assignment methodologies, a radio carrier’s numerology is typically fixed for any given QoS flow, as directed by the QoS requirements. Unfortunately, a drawback to 5G’s radio carrier numerology assignment approach is that it does not account for the impact of multi-path/delay spread. As such 5G is unable to efficiently utilize the allocated radio spectrum in high delay spread radio environments, thus potentially limiting both massive Machine Type Communication (mMTC) and ultra Reliable Low Latency Communication’s (uRLLC) ability to meet each data flow’s Quality of Service (QoS) requirements; low latency flows are more sensitive to high delay spread. When considering power-domain NOMA resource allocation, the impact of delay spread can only be partially mitigated. In this research work we derive an optimal QoS to 5G radio carrier numerology mapping methodology for NOMA-enabled 5G Heterogeneous groupcast networks, subject to the constraints imposed by the UEs and UE-to-Network Relay. Compared to legacy multicast methodologies, our methodology can achieve up to a 4.7 × higher resource block capacity while minimizing each resource block’s latency deviation from its original latency requirements, i.e., compared to legacy methodologies, our methodology reduces QoS flow latency while minimizing resource block latency deviation. © 2021, The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd.