Performance Analysis of MEC Based on NOMA under Imperfect CSI with Eavesdropper

Xuehua Li,Xinwei Yue,Yafei Wang,Yingjie Pei,Huan Jiang,Yuqiao Suo,Xingwang Li

doi:10.1155/2021/2700843

Abstract

Mobile edge computing (MEC) is becoming more and more popular because of improving computing power in virtual reality, augmented reality, unmanned driving, and other fields. This paper investigates a nonorthogonal multiple access- (NOMA-) based MEC system, which is under imperfect channel state information (ipCSI). In this system model, a pair of users offloads their tasks to the MEC server with the existence of an eavesdropper (Eve). To evaluate the impact of Eve on the performance of the NOMA-MEC system, the secrecy outage probability (SOP) expressions for two users with the conditions of imperfect CSI and perfect channel state information (pCSI) are derived. In addition, both throughput and energy efficiency are discussed in the delay-limited transmission mode. Simulation results reveal that (1) due to the influence of channel estimation errors, the secrecy outage behaviors of two users under ipCSI conditions are worse than those of users with pCSI; (2) the secrecy performance of NOMA-MEC is superior to orthogonal multiple access- (OMA-) aided MEC systems; and (3) the NOMA-MEC systems have the ability to attain better system throughput and energy efficiency compared with OMA-MEC.

Highlights

As the mobile communication systems develop rapidly, the technical standards have constantly evolved
This paper mainly investigates the integration of nonorthogonal multiple access (NOMA) and Mobile edge computing (MEC) by taking imperfect channel state information (ipCSI) and perfect channel state information into account, i.e., considering the Eve in the NOMA uplink-assisted MEC scenarios with channel estimation errors
We have studied the secrecy performance of uplink NOMAMEC under ipCSI and pCSI conditions with an Eve

Summary

Introduction

As the mobile communication systems develop rapidly, the technical standards have constantly evolved. Considering the resource constraints and interference between multiple users, the authors of [12] designed an iterative MEC resource allocation algorithm which operated heuristically to make dynamic offloading decisions and confirmed that this method overmatches the cloud computing solutions in the field of execution delay and offloading efficiency. To improve the offloading efficiency of edge users, a NOMA-assisted MEC system was introduced in [17], where a joint communication and computation resource iterative optimization algorithm with low complexity was proposed to minimize the energy consumption. In order to further evaluate the eavesdropping ability of users without knowing the CSI of the Eve, the authors in [23] proposed an effective iterative algorithm to maximize the minimum antieavesdropping ability of uplink NOMA users by jointly formulating the security rate, locally calculating bits, and allocating power. As the channel estimation errors increase, the system throughput and energy efficiency of NOMA-MEC decrease seriously

System Model

Performance Analysis

Results and Discussion

Conclusions