scholarly journals Using delta-sigma modulators in visible light OFDM systems

Author(s):  
Zhenhua Yu ◽  
Arthur J. Redfern ◽  
G. Tong Zhou
Author(s):  
T. Deepa ◽  
Harshita Mathur ◽  
K. A. Sunitha

<span lang="EN-US">Visible Light Communication (VLC) has become an accolade to its radio frequency counterpart. In VLC system, orthogonal frequency division multiplexing (OFDM) has drawn much attention, because of simple equalization, high spectral efficiency, high data rate and robustness to intersymbol interference (ISI). Besides, there are emerging applications that ought to be gotten with low latency and high reliability. To diminish power requirements with no transmission capacity extension, Trellis coded modulation (TCM) is utilized as a part of the framework in which the free distance of trellis diagram is equivalent to the minimum distance between the points of constellation focuses in partitioned subsets, which augments the coding gain up i.e. the performance parameter viably. TCM together with VLC-OFDM enhances the transmission execution in reasonable frameworks. In this paper, we propose OFDM which is based on TCM and is planned and exeuted for digitized OFDM frameworks by presenting delta sigma modulation (DSM) considering VLC channel. Simulation results show that the proposed TCM based VLC-OFDM offers incredible robustness against noises and nonlinear degradation.</span>


2017 ◽  
Vol 44 (8) ◽  
pp. 0806003 ◽  
Author(s):  
贾科军 Jia Kejun ◽  
靳 斌 Jin Bin ◽  
郝 莉 Hao Li ◽  
张守琴 Zhang Shouqin

Author(s):  
Xintong Ling ◽  
Jiaheng Wang ◽  
Xiao Liang ◽  
Zhi Ding ◽  
Chunming Zhao

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5512
Author(s):  
Motoi Kodama ◽  
Shinichiro Haruyama

There is a unique transmission method of visible light communication (VLC) that can transmit multiple data in multiple directions simultaneously by using a projector with the digital micro-mirror device (DMD). Previously, we proposed a method of transmitting data from the projector that transmits digitally modulated VLC signal from each pixel, and in this paper, we propose an extension of the method to transmit audio signal by using a special type of modulation called delta-sigma-modulation (DSM). The DSM-VLC system employs a simple receiver that comprises simple analog electric circuits, which contribute to low power consumption. We made a DSM-VLC prototype and verified that the prototype was able to send four different waves to different directions. Additionally, the experiments’ results agree very well with the simulation results. Furthermore, we designed two types of DSM: pulse width modulation (PWM) and pulse density modulation (PDM), and we verified that the PDM-VLC is better than the PWM-VLC regarding the DMD switching frequency’s efficiency. Our proposed DSM-VLC can be used for such applications as voice information guidance systems with direction-selective messages.


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