# Optimal Configuration of Reconfigurable Intelligent Surfaces with Arbitrary Discrete Phase Shifts

arXiv: https://arxiv.org/abs/2311.07096 · HTML: https://mlsanity.com/paper/2311.07096/

## Key facts

- Cited by 1 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 13 Nov 2023.

## Built on by (most cited first, 1 of 1)

- [Optimal Configuration of Reconfigurable Intelligent Surfaces With Non-uniform Phase Quantization](https://mlsanity.com/paper/2405.06967/) (2024)

## Abstract (arXiv)

We address the reflection optimization problem for a reconfigurable intelligent surface (RIS), where the RIS elements feature a set of non-uniformly spaced discrete phase shifts. This is motivated by the actual behavior of practical RIS elements, where it is shown that a uniform phase shift assumption is not realistic. A problem is formulated to find the optimal refection amplitudes and reflection phase shifts of the RIS elements such that the channel capacity of the target user is maximized. We first prove that in the optimal configuration, each RIS element is either turned off or operates at maximum amplitude. We then develop a method that finds the optimal reflection amplitudes and phases with complexity linear in the number of RIS elements. Some new and interesting insight into the reflection optimization problem is also provided.