Optimal Energy Efficiency Used DDPG in IRS-NOMA Wireless Communications

Abstract

Combining Intelligent Reflecting Surface (IRS) with Non-Orthogonal Multiple Access (NOMA) technology is a viable option for increasing communication performance. Firstly, a NOMA downlink transmission system assisted by IRS is established in this study, for maximizing its energy efficiency. Then a Deep Deterministic Policy Gradient (DDPG) algorithm with symmetric properties is used to further optimize the energy efficiency of the system by intelligently adjusting the beam-forming matrix of the access point (AP) and the phase-shift matrix of the IRS. According to the simulation results, the proposed IRS-assisted NOMA downlink network based on the DDPG algorithm presented a considerably higher energy efficiency than the orthogonal multiple access network.

Keywords

• intelligent reflecting surface
• deep deterministic policy gradient
• non-orthogonal multiple access