Abstract
In this paper, an IRS-Aided integrated sensing and communications (ISAC) system operating in the terahertz (THz) band is proposed to maximize the system capacity. Transmit beamforming and phase-shift design are transformed into a universal optimization problem with ergodic constraints. Then the joint optimization of transmit beamforming and phase-shift design is achieved by gradient-based, primal-dual proximal policy optimization (PPO) in the multi-user multiple-input single-output (MISO) scenario. Specifically, the actor part generates continuous transmit beamforming and the critic part takes charge of discrete phase shift design. Based on the MISO scenario, we investigate a distributed PPO (DPPO) framework with the concept of multi-Threading learning in the multi-user multiple-input multiple-output (MIMO) scenario. Simulation results demonstrate the effectiveness of the primal-dual PPO algorithm and its multi-Threading version in terms of transmit beamforming and phase-shift design.
Original language | English (US) |
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Pages (from-to) | 2056-2069 |
Number of pages | 14 |
Journal | IEEE Journal on Selected Areas in Communications |
Volume | 40 |
Issue number | 7 |
DOIs | |
State | Published - Jul 1 2022 |
All Science Journal Classification (ASJC) codes
- Computer Networks and Communications
- Electrical and Electronic Engineering
Keywords
- Integrated sensing and communications
- distributed reinforcement learning
- intelligent reflecting surface
- phase shift design
- transmit beamforming