Computation bits maximization in backscatter-assisted wireless-powered NOMA-MEC networks.

In the field of Internet-of-Things (IoT), how to enhance the computation capacity and prolong the life span of massive smart IoT nodes is becoming a more practically important but challenging problem. In this paper, we propose a backscatter-assisted wireless-powered non-orthogonal multiple access (NOMA)-mobile edge computing (MEC) network, where IoT nodes harvest energy from signals transmitted by a dedicated energy source and then offload data to the MEC server via backscattering and uplink NOMA. To exploit its potential performance, we formulate a non-convex problem to maximize the total computation bits of all the IoT nodes by jointly optimizing the communication resource of each IoT node and the computation resource of both the IoT nodes and the MEC server. By introducing a slack variable and a series of auxiliary variables as well as using the contradiction and inequality transformation approaches, we transform the original non-convex problem into a convex one and devise an iterative algorithm to optimally solve it. Simulation results are provided to demonstrate the quick convergence of the proposed iterative algorithm and to confirm the superiority of the proposed scheme over the existing benchmark schemes. [ABSTRACT FROM AUTHOR]