Resource allocation in PD-NOMA-based mobile edge computing system: Multiuser and multitask priority

Mobile edge computing (MEC) is a new network architecture concept that enables cloud computing capabilities at the edge of the cellular network, and hence, MEC has the ability to process the computation tasks in close proximity to the network edge. In this paper, we consider a multiuser MEC system with multiple computation tasks such that each computation task is independent with different priorities. For this purpose, we devise a novel multiuser, multitask, and nonpreemptive priority M/G/1 queuing model in the MEC server environment. In doing so, we propose a priority-based task scheduling policy that aims to maximize the profit of mobile network operator by jointly optimizing service rate, transmit power, and subcarrier allocation with satisfying power and delay constraints. This is necessary to handle the physical channel opportunities to obtain higher spectral efficiency in the proposed task offloading scheme. In this line, we also consider power-domain nonorthogonal multiple access (PD-NOMA) technique. Numerical results show that, by using the Priority queuing in PD-NOMA-SCA and Priority queuing in PD-NOMA-matching schemes, the performance can be improved considerably compared to No-priority queuing in OMA-SCA and No-priority queuing in OMA-matching, eg, the Priority queuing in PD-NOMA-SCA scheme improves nearly 54% compared to the No-priority queuing in OMA-SCA scheme. It is noteworthy that the performance gap between exhaustive search and the Priority queuing in PD-NOMA-SCA scheme is nearly 7%.