5 Gbps Optical Wireless Communication Using Commercial SPAD Array Receivers

TL;DR

This paper demonstrates a 5 Gbps optical wireless communication system using commercial SPAD array receivers, employing advanced techniques to overcome nonlinearity and optimize data rate performance.

Contribution

It introduces a novel combination of nonlinear equalization, power ratio optimization, and adaptive loading to achieve record data rates with SPAD-based OWC systems.

Findings

Achieved 5 Gbps data rate experimentally.

Compared OFDM and OOK modulation schemes.

Identified optimal operational regimes for each scheme.

Abstract

Photon counting detectors such as single-photon avalanche diode (SPAD) arrays can be utilized to improve the sensitivity of optical wireless communication (OWC) systems. However, the achievable data rate of SPAD-based OWC systems is strongly limited by the nonlinearity induced by SPAD dead time. In this work, the performance of SPAD-based OWC system with orthogonal frequency division multiplexing (OFDM) is investigated and compared with that of on-off keying (OOK). We employ nonlinear equalization, peak-to-average power ratio optimization by adjusting the OFDM clipping level, and adaptive bit and energy loading to achieve a record experimental data rate of 5 Gbps. The contrasting optimal regimes of operation of the two modulation schemes are also demonstrated.