High data rate multiple input multiple output (MIMO) optical wireless communications using white led lighting

TLDR

Solid‑state lighting, especially white LED sources, is rapidly expanding due to its reliability and high efficiency, and these LEDs can also serve as data transmitters in visible‑light communications, though their limited modulation bandwidth (~MHz) poses a challenge that optical MIMO techniques may overcome by enabling parallel transmission across LED arrays. This study examines non‑imaging versus imaging MIMO approaches for white‑LED optical wireless links, aiming to determine which configuration supports reliable data transmission across all receiver positions. The authors compare a non‑imaging MIMO system, which suffers from symmetry‑induced performance degradation, with an imaging‑based MIMO system that maintains proper operation under all foreseeable receiver geometries. Simulations indicate that imaging‑based MIMO can achieve several hundred megabits per second and, in many scenarios, reach gigabit‑per‑second data rates.

Abstract

Solid-state lighting is a rapidly growing area of research and applications, due to the reliability and predicted high efficiency of these devices. The white LED sources that are typically used for general illumination can also be used for data transmission, and Visible Light Communications (VLC) is a rapidly growing area of research. One of the key challenges is the limited modulation bandwidth of sources, typically several MHz. However, as a room or coverage space would typically be illuminated by an array of LEDs there is the potential for parallel data transmission, and using optical MIMO techniques is potentially attractive for achieving high data rates. In this paper we investigate non-imaging and imaging MIMO approaches: a non-imaging optical MIMO system does not perform properly at all receiver positions due to symmetry, but an imaging based system can operate under all foreseeable circumstances. Simulations show such systems can operate at several hundred Mbit/s, and up to Gbit/s in many circumstances.