Real-time Audio &Video Transmission System Based on Visible Light Communication

With the increasing popularity of solid sate lighting devices, Visible Light Communication (VLC) is globally recognized as an advanced and promising technology to realize short-range, high speed as well as large capacity wireless data transmission. In this paper, we propose a prototype of real-time audio and video broadcast system using inexpensive commercially available light emitting diode (LED) lamps. Experimental results show that real-time high quality audio and video with the maximum distance of 3 m can be achieved through proper layout of LED sources and improvement of concentration effects. Lighting model within room environment is designed and simulated which indicates close relationship between layout of light sources and distribution of illuminance.

Channel Simulation of Non-imaging Optical MIMO Communication

This paper reports a channel simulation of an indoor optical wireless multiple-input-multiple-output (MIMO) system with non-imaging receivers. The system consists of a 2×2 array of white light-emitting diodes (LEDs) and 2×2 array of PDs. An overview of the model specifications, channel impulse response and channel capacity are demonstrated in this paper. The distribution of the first reflection is analyzed. The effect of SNR and the location of receivers on non-imaging optical MIMO communications are investigated. In addition, by moving the receivers, the optimal location of the communication is found.

Design of Wireless Optical Access System using LED

This paper develops a prototype to demonstrate a full-duplex wireless visible light communication (VLC) system based on Universal Serial Bus (USB) port. Combing with a USB 2.0 port on one board, it can achieve up to 2 Mbps bit rates error free, which is mainly limited to the USB bridge circuit, between two computers for data transmission, such as text, audio and video. Hyper Terminal and self-written software are used to allow setting the transmission data rate, control bits, check bits and achieve real-time transmission between any two mobile devices with a USB port. The work is based on the research of VLC local access network. This paper also shows the experimental results and the relationship between system transmission eye diagram and bit rate.

Prospective study of probiotic supplementation results in immune stimulation and improvement of upper respiratory infection rate

The human gut microbiota is an important environmental factor for human health with evolutionarily conserved roles in immunity,metabolism,development,and behavior of the host.Probiotic organisms are claimed to offer several functional properties including stimulation of immune system.The purpose of this study is to investigate the effects of a probiotic supplementation on adult volunteers who have contracted the common cold four or more times in the past year.This study is a single center,doubleblind,randomized,controlled,prospective trial.Subjects received a probiotic drink containing Lactobacillus paracasei(at least 3×10^7 colony forming units(CFU)ml^-1),Lactobacillus casei 431®(at least 3×10^7 CFU ml1)and Lactobacillus fermentium PCC®(at least 3×10^6 CFU ml^-1)or an identical placebo without probiotics for a 12-week study period.The consumption of probiotics significantly reduced the incidence of upper respiratory infection(p<0.023)and flu-like symptoms with an oral temperature higher than 38℃(p<0.034)as compared to the placebo group.Subjects that consumed probiotics demonstrated a significantly higher level of IFN-g in the serum(p<0.001)and sIgA in the gut(p<0.010)as compared to the placebo group and a significant higher level of serum IFN-g(p<0.001)and gut sIgA(p<0.001)as compared to their baseline test results.In contrast,there were no significant differences in the serum IL-4,IL-10,IgA,IgG or IgM between the probiotics and the placebo groups.Results of this study demonstrated that probiotics were safe and effective for fighting the common cold and influenza-like respiratory infections by boosting the immune system.