Abstract
Mobile wireless communication heavily relies on the radio frequency to convey message and data. However, its limited spectrum can hardly meet the demands for the future high data rate applications. Optical wireless communication, in particular visible light communication, opens up vast optical spectrum for communication, and meanwhile can retrofit the light sources as the communication transmitters in the existing working or living environments. In conjunction with the ubiquitous cameras in hand-held consumer electronics such as smartphones and pads, optical camera communication (OCC) further takes advantages of image sensors as the communication receivers and realizes low-cost communication systems. This article first provides an overview of OCC systems. It then addresses some practical constraints, ranging from sensor low frame rate and instability, rolling shutter readout, to visual qualities of displayed images and videos, and link blockage between the transmitter and receiver. Accordingly, it introduces existing and new solutions to deal with those constraints by data modulation, newly developed camera structures, post-processing of sensed signals and non-line of sight OCC as a new form. In particular, indirect paths by either the indoor surface reflection or the outdoor atmospheric scattering are explored for link connectivity under blockage. Finally, some future research directions are suggested.This article is part of the theme issue ‘Optical wireless communication’.
Highlights
Traditional radio frequency (RF) communication techniques have been developed tremendously over the recent decades. It is not yet entirely clear what the next-generation technologies will provide, they aim at higher transmission speeds, lower latency, improved spectral efficiency, higher network capacity, and lower power consumption and cost [1]
Several hybrid modulations standardized in PHY V and PHY VI include rolling shutter-FSK (RS-FSK) [32], compatible m-ary frequency shift keying series (CM-FSK) [33,34] and compatible OOK (C-OOK) [32], mirror pulse modulation (MPM), asynchronous quick link (A-QL) [35], variable transparent amplitude shape code (VTASC) [35], sequential scalable twodimensional colour (SS2DC), invisible data embedding (IDE) and hidden asynchronous quick link (HA-QL) [35]
Premachandra et al [88] proposed an optical flow-based visible light communication (VLC) tracking system by using an on-vehicle high-frame-rate (HFR) camera working at 1000 fps cooperated with an light-emitting diodes (LEDs) array changing at 500 Hz
Summary
Traditional radio frequency (RF) communication techniques have been developed tremendously over the recent decades It is not yet entirely clear what the next-generation technologies will provide, they aim at higher transmission speeds, lower latency, improved spectral efficiency, higher network capacity, and lower power consumption and cost [1]. Leveraging the lower attenuation of optical signals in the IR spectrum while penetrating the atmosphere, FSO communication typically adopts an IR laser diode (LD) or other types of laser as the transmitter rather than an LED in VLC and LiFi, achieving several thousand kilometres via a point-to-point link [16]. Compared to other OWC technologies, OCC has the unique features such as the larger receiver field-of-view (FOV), spatial and wavelength separation ability, and low cost In some applications such as indoor positioning and navigation, vehicle steering, and remote controlling, cost and accuracy may be the main factors to consider rather than data rate. Comparisons of different OWC technologies are summarized in table 1, showing their key characteristics, respectively
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
