Design and Optimisation of High-Speed Receivers for 6G Optical Wireless Networks

TL;DR

This paper presents a systematic design and optimization of high-speed multi-tier non-imaging angle diversity receivers with compound parabolic concentrators for 6G optical wireless networks, achieving 12 Gb/s data rates in compact form.

Contribution

It introduces a novel optimization framework for designing ADRs with CPCs, balancing gain, FOV, and bandwidth, and proposes techniques to reduce receiver size while maintaining high data rates.

Findings

A compact ADR of ≤0.5 cm height achieves 12 Gb/s at 3 m.

Optimal configurations balance gain-FOV and area-bandwidth tradeoffs.

Design guidelines are provided through extensive simulations.

Abstract

To achieve multi-Gb/s data rates in 6G optical wireless access networks based on narrow infrared (IR) laser beams, a high-speed receiver with two key specifications is needed: a sufficiently large aperture to collect the required optical power and a wide field of view (FOV) to avoid strict alignment issues. This paper puts forward the systematic design and optimisation of multi-tier non-imaging angle diversity receivers (ADRs) composed of compound parabolic concentrators (CPCs) coupled with photodiode (PD) arrays for laser-based optical wireless communication (OWC) links. Design tradeoffs include the gain-FOV tradeoff for each receiver element and the area-bandwidth tradeoff for each PD array. The rate maximisation is formulated as a non-convex optimisation problem under the constraints on the minimum required FOV and the overall ADR dimensions to find optimum configuration of the receiver bandwidth and FOV, and a low-complexity optimal solution is proposed. The ADR performance is studied using computer simulations and insightful design guidelines are provided through various numerical examples. An efficient technique is also proposed to reduce the ADR dimensions based on CPC length truncation. It is shown that a compact ADR with a height of $\leq0.5$ cm and an effective area of $\leq0.5$ cm$^2$ reaches a data rate of $12$ Gb/s with a half-angle FOV of $30^\circ$ over a $3$ m link distance.