一种基于混合 NOMA 的 IRS-MEC 系统 能量效率优化方案.

In MEC combining IRS and resource allocation strategies to improve system energy efficiency is a current hot topic of research at home and abroad. This paper aimed to maximize energy efficiency in IRS-assisted MEC system through joint optimization of the computing frequency at users, transmit power and time, and the IRS discrete phase-shift based on the transmission mode of hybrid non-orthogonal multiple access. Since the optimization process involved non-convex fractional programming problems that are difficult to solve, this paper proposed a Dinkelbach-SCA algorithm with two iterative-steps. Firstly, this paper converted the initial problem into a tractable form via Dinkelbach' s method, optimization of IRS discrete phase shift by separating variables. Then, by introducing auxiliary variables, and leveraging successive convex approximation, the paper decoupled the relationship between transmit power and time while converted the non-convex problem to a convex one. Hence, the paper could obtain optimal solution. The simulation results show that the energy efficiency of the proposed system scheme is better than other comparison ones, and the energy efficiency of the system increases with the decrease of the minimum computational data amount of user 2. [ABSTRACT FROM AUTHOR]