Energy-Efficient Precoding for Dense VCSEL-Based OWC Systems Under a Cooperative Broadcast Model

TL;DR

This paper introduces a scalable precoding framework for dense VCSEL-based optical wireless communication systems that maximizes energy efficiency while ensuring user rate requirements, addressing interference challenges in next-generation networks.

Contribution

It presents a novel non-convex optimization approach using Dinkelbach's method and inner approximation for energy-efficient precoding in dense VCSEL-based OWC systems.

Findings

Outperforms regularized zero-forcing in energy efficiency

Effective in large-scale dense VCSEL deployments

Ensures minimum user rate constraints

Abstract

As 6G and beyond aim for sustainable, high-capacity wireless connectivity, optical wireless communication (OWC) has emerged as a compelling solution.Recent advances in vertical-cavity surface-emitting laser (VCSEL) arrays have significantly enhanced OWC performance, enabling high-speed, low-power data transmission. However, dense VCSEL deployments introduce challenges related to interference and energy efficiency (EE). This paper proposes a scalable precoding framework for EE maximization in fully cooperative VCSEL-based OWC broadcast systems. We formulate a non-convex optimization problem to design the precoding matrix under practical optical constraints while guaranteeing minimum user rates. To solve this, we apply Dinkelbach's method to handle the fractional objective and the inner approximation technique to iteratively convexify and solve the problem. Simulation results show that our approach consistently outperforms regularized zero-forcing in terms of EE, particularly in large-scale deployments, demonstrating its potential for next-generation sustainable dense OWC networks.