Abstract
Optimizing discrete phase shifts in large-scale reconfigurable intelligent surfaces (RISs) is challenging due to their non-convex and non-linear nature. In this letter, we propose a heuristic-integrated deep reinforcement learning (DRL) framework that (1) leverages accumulated actions over multiple steps in the double deep Q-network (DDQN) for RIS column-wise control and (2) integrates a greedy algorithm (GA) into each DRL step to refine the state via fine-grained, element-wise optimization of RIS configurations. By learning from GA-included states, the proposed approach effectively addresses RIS optimization within a small DRL action space, demonstrating its capability to optimize phase-shift configurations of large-scale RISs.
| Original language | English |
|---|---|
| Pages (from-to) | 1579-1583 |
| Number of pages | 5 |
| Journal | IEEE Communications Letters |
| Volume | 29 |
| Issue number | 7 |
| Early online date | 9 May 2025 |
| DOIs | |
| Publication status | Published - 1 Jul 2025 |
Bibliographical note
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