Abstract

Multi-access Edge Computing (MEC) has recently emerged as a potential technology to serve the needs of mobile devices (MDs) in 5G and 6G cellular networks. By offloading tasks to high-performance servers installed at the edge of the wireless networks, resource-limited MDs can cope with the proliferation of the recent computationally-intensive applications. In this thesis, we study the computation offloading problem in a massive multiple-input multiple-output (MIMO)-based MEC system where the base stations are equipped with a large number of antennas. Our objective is to minimize the power consumption and offloading delay at the MDs under the stochastic system environment. To this end, we introduce a new formulation of the problem as a Markov Decision Process (MDP) and propose two Deep Reinforcement Learning (DRL) algorithms to learn the optimal offloading policy without any prior knowledge of the environment dynamics. First, a Deep Q-Network (DQN)-based algorithm to solve the curse of the state space explosion is defined. Then, a more general Proximal Policy Optimization (PPO)-based algorithm to solve the problem of discrete action space is introduced. Simulation results show that our DRL-based solutions outperform the state-of-the-art algorithms. Moreover, our PPO algorithm exhibits stable performance and efficient offloading results compared to the benchmarks DQN and Double DQN (DDQN) strategies.