IRS-aided Wireless Powered MEC Systems: TDMA or NOMA for Computation Offloading?

by   Guangji Chen, et al.

An intelligent reflecting surface (IRS)-aided wireless powered mobile edge computing (WP-MEC) system is conceived, where each device's computational task can be divided into two parts for local computing and offloading to mobile edge computing (MEC) servers, respectively. Both time division multiple access (TDMA) and non-orthogonal multiple access (NOMA) schemes are considered for uplink (UL) offloading. Given the capability of IRSs in intelligently reconfiguring wireless channels over time, it is fundamentally unknown which multiple access scheme is superior for MEC UL offloading. To answer this question, we first investigate the impact of three different dynamic IRS beamforming (DIBF) schemes on the computation rate of both offloading schemes, based on the flexibility for the IRS in adjusting its beamforming (BF) vector in each transmission frame. Under the DIBF framework, computation rate maximization problems are formulated for both the NOMA and TDMA schemes, respectively, by jointly optimizing the IRS passive BF and the resource allocation. We rigorously prove that offloading adopting TDMA can achieve the same computation rate as that of NOMA, when all the devices share the same IRS BF vector during the UL offloading. By contrast, offloading exploiting TDMA outperforms NOMA, when the IRS BF vector can be flexibly adapted for UL offloading. Despite the non-convexity of the computation rate maximization problems for each DIBF scheme associated with highly coupled optimization variables, we conceive computationally efficient algorithms by invoking alternating optimization. Our numerical results demonstrate the significant performance gains achieved by the proposed designs over various benchmark schemes.


page 1

page 2

page 3

page 4


Computation Efficiency Maximization in Wireless-Powered Mobile Edge Computing Networks

Energy-efficient computation is an inevitable trend for mobile edge comp...

Resource Management for IRS-assisted WP-MEC Networks with Practical Phase Shift Model

Wireless powered mobile edge computing (WP-MEC) has been recognized as a...

IRS Aided MEC Systems with Binary Offloading: A Unified Framework for Dynamic IRS Beamforming

In this paper, we develop a unified dynamic intelligent reflecting surfa...

Intelligent Reflecting Surface Aided Wireless Energy Transfer and Mobile Edge Computing for Public Transport Vehicles

In the forthcoming 6G era, Future Public transport vehicles (F-PTV), suc...

Computation Rate Maximization in Wireless Powered MEC with Spread Spectrum Multiple Access

The integration of mobile edge computing (MEC) and wireless power transf...

Energy Efficient Reconfigurable Intelligent Surface Enabled Mobile Edge Computing Networks with NOMA

Reconfigurable intelligent surface (RIS) has emerged as a promising tech...

Energy-Latency Aware Intelligent Reflecting Surface Aided Multi-cell Mobile Edge Computing

The explosive development of the Internet of Things (IoT) has led to inc...

Please sign up or login with your details

Forgot password? Click here to reset