Joint Power and Time Allocation for NOMA–MEC Offloading

This correspondence considers non-orthogonal multiple access (NOMA) assisted mobile edge computing (MEC), where the power and time allocation is jointly optimized to reduce the energy consumption of computation offloading. Closed-form expressions for the optimal power and time allocation solutions are obtained and used to establish the conditions for determining whether the conventional orthogonal multiple access (OMA), pure NOMA or hybrid NOMA should be used for MEC offloading.

I. Introduction

Both non-orthogonal multiple access (NOMA) and mobile edge computing (MEC) have been recognized as important techniques in future wireless networks [1], [2]. Sophisticated optimization frameworks developed in [3], [4] show that by applying NOMA to MEC, not only can severe delay be avoided, but also energy consumption can be reduced, although the comparisons between NOMA and orthogonal multiple access (OMA) in [3], [4] rely on simulation. Insightful analytical results developed in [5] confirmed the advantages of NOMA-MEC offloading, by using fixed bandwidth allocation.