RIS-Enabled Cellular Systems Operated by Different Service Providers

TL;DR

This paper proposes a Riemannian manifold optimization-based method to design RIS reflection coefficients, enhancing the performance of a specific cell while reducing interference to other cells in multi-provider cellular systems.

Contribution

It introduces a novel RIS reflection coefficients design approach that balances performance enhancement and interference mitigation across multiple service provider cells.

Findings

Effective performance improvement for targeted cells.

Reduced interference to other cells.

Numerical results confirm the method's practicality.

Abstract

In realistic cellular communication systems, multiple service providers will operate within different frequency ranges. Each serving cell, which is managed by a distinct service provider, is designed individually due to the orthogonal frequencies. However, when a reconfigurable intelligent surface (RIS) is deployed for a certain cell, the RIS still incurs reflective channels for the overall system since the RIS reflects signals across all frequency ranges. This may cause severe undesired performance degradation for the other cells unless the reflection coefficients are properly designed. To tackle this issue, by utilizing the Riemannian manifold optimization method, an RIS reflection coefficients design is proposed in this paper to maximize the performance improvements of the cell that deploys the RIS while minimizing the undesired performance degradation for the other cells simultaneously. Numerical results demonstrate that the proposed design can effectively balance the two objectives for practical scenarios.