Undersampled pulse width modulation for optical camera communications

Luo, P; Jiang, T; Haigh, PA; Ghassemlooy, Z; Zvanovec, S

doi:10.1109/ICCW.2018.8403732

Undersampled pulse width modulation for optical camera communications

Lookup NU author(s): Dr Paul Haigh ORCiD

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This is the authors' accepted manuscript of a conference proceedings (inc. abstract) that has been published in its final definitive form by IEEE, 2018.

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Abstract

© 2018 IEEE. An undersampled pulse width modulation (UPWM) scheme is proposed to enable users to establish a non- flickering optical camera communications (OCC) link. With UPWM, only a digital light emitting diode (LED) driver is needed to send signals using a higher order modulation. Similar to other undersample-based modulation schemes for OCC, a dedicated preamble is required to assist the receiver to indicate the phase error introduced during the undersampling process, and to compensate for nonlinear distortion caused by the in-built gamma correction function of the camera. To test the performance of the UPWM- based OCC system, an experimental test-bed is developed. The experimental results show that the proposed system is able to achieve a data rate of 150 bps (spectrum efficiency of 5 bits/symbol) at a bit error rate of 6.76×10^-4, which is well below the forward error correction limit of 3.8×10^-3, over a link span of 1 m using a Huawei Nexus 6P smartphone with a frame rate of 30 fps.