Hierarchical Colour-Shift-Keying Aided Layered Video Streaming for the Visible Light Downlink

Abstract

Colour-shift keying (CSK) constitutes an important modulation scheme conceived for the visible light communications (VLC). The signal constellation of CSK relies on three different-colour light-sources invoked for information transmission. The CSK constellation has been optimized for minimizing the bit error rate, but no effort has been invested in investigating the feasibility of CSK aided unequal error protection (UEP) schemes conceived for video sources. Hence in this treatise, we conceive a hierarchical CSK (HCSK) modulation scheme based on the traditional CSK, which is capable of generating interdependent layers of signals having different error probability, which can be readily reconfigured by changing its parameters. Furthermore, we conceived a HCSK design example for transmitting scalable video sources with the aid of a recursive systematic convolutional (RSC) code. An optimisation method is conceived for enhancing the UEP and for improving the quality of the received video. Our simulation results show that the proposed optimized-UEP 16-HCSK-RSC system outperforms the traditional EEP scheme by about 1.7 dB of optical SNR at a peak signal-to-noise ratio (PSNR) of 37 dB, whilst optical SNR savings of up to 6.5 dB are attained at a lower PSNR of 36 dB.

Optimization of Visible-Light Optical Wireless Systems: Network-Centric Versus User-Centric Designs

“…The hierarchical structure of the videostream also facilitates energy-efficient video communications by jointly considering the scalable video quality and the power consumption, as demonstrated for traditional RF networks in [174]- [176]. However, there is a paucity of studies on scalable video transmission in VLC-based systems [91], [177]. To fill this gap in the literature, Zhu et al [177] conceived a CSK-aided unequal-error-protection scheme for layered video streaming in a VLC DL system, which outperformed the traditional equal error protection scheme.…”

“…However, there is a paucity of studies on scalable video transmission in VLC-based systems [91], [177]. To fill this gap in the literature, Zhu et al [177] conceived a CSK-aided unequal-error-protection scheme for layered video streaming in a VLC DL system, which outperformed the traditional equal error protection scheme. Moreover, Li et al [91] further explored the energy efficiency of UC-VLC networks and designed an efficient scalable video system relying on dynamic UC cluster formation by jointly considering both the video-related and the VLC-related characteristics.…”

Reduced-Complexity Iterative Receiver for Improving the IEEE 802.15.7 Convolutional-Coded Color Shift Keying Mode

“…The research fraternity has primarily focused on optimizing the CSK constellations [3]- [5]. However, recently a soft-decision aided CSK detector was conceived [6] for iterative CSK transceivers, while CSK aided unequal error protection schemes were developed in [7] for video applications. The concatenated CSK-aided code designs of [6] invoke bit-based iterative decoding, which either requires improved bit-to-symbol mapping strategies or a three-stage concatenated system for achieving a vanishingly low Bit Error Ratio (BER).…”

“…In this paper, we consider a non-dispersive AWGN channel [6], [7], hence H is equivalent to the identity matrix. Furthermore, we define the electrical SNR as γ e = E s /N 0 , where E s = E{||s|| 2 }, while N 0 is the total electrical noise power.…”

Unary-Coded Dimming Control Improves ON-OFF Keying Visible Light Communication

“…Visible Light Communication (VLC) [1]- [4] has emerged as a potential complement to the classic Radio Frequency (RF) based communication, particularly in short range indoor applications. In contrast to RF systems, which rely on the scarce RF spectrum, VLC harnesses the abundant licensefree visible light band (400 to 800 THz) for supporting both illumination as well as communication.…”