Energy-efficient Resource Allocation for Intelligent Reflecting Surface Aided MEC Networks

Abstract

In this paper, we consider the physical layer security for a mobile edge computing (MEC) network where multiple single-antenna users aim to securely offload partial computation tasks simultaneously to an access point (AP) integrated with an MEC server by leveraging an intelligent reflecting surface (IRS) in the presence of a multi-antenna eavesdropper. A friendly jammer is further introduced to improve transmission secrecy. We formulate a problem of minimizing the sum energy consumption by jointly designing the allocation of computation bits for local computing and offloading, the transmit power of both users and jammer, the multi-user detection matrix at the AP, and the phase shift matrix at the IRS. The formulated problem is a non-convex problem that is hard to tackle directly, so we decompose it into tractable subproblems and develop an alternating optimization approach by combing semidefinite relaxation algorithm. Numerical results are provided to demonstrate the effectiveness of the proposed scheme and the benefit of deploying an IRS for achieving a secure and energy-efficient MEC network.