High-efficiency Visible Light Indoor Environment Sensing And Communication

With the development of light-emitting diode(LED)technology,LED lighting is gradually replacing the other traditional lighting modalities,the potential possibility of using LED in the sensing and communication system has received extensive attention from researchers in recent years.In practical applications and systems,combining the characteristics of the visible channel to design the system can greatly improve the energy efficiency of the system.Take advantages of the characteristics of visible light chan-nel,this paper mainly focus on explore the energy efficient indoor visible light sensing(VLS)scheme and the energy efficient constellation design scheme of visible light com-munication(VLC)system under the influence of signal-dependent noise(SDN).For energy-efficient system design of VLS systems in visible light channels,we di-rectly use existing high-efficiency LEDs to sense and detect the environment to achieve an energy-efficient VLS system.The indoor visible light environment sensing can be perceived based on the eigen space analysis and detection method.Compared with the traditional detection method based on the average intensity variation(AIV),the detec-tion method based on eigen space analysis has higher perception accuracy in the detec-tion of the change of environment.Considering the implementation of the VLS-based channel estimation update scheme,the channel is updated only if the change of the in-door environment has been detected,so that the channel estimation overhead can be reduced without the loss of the SER performance.The energy-efficient constellation design without the need for extra DC bias under the influence of SDN is considered for a single-user VLC system under visible light channel.In the single-carrier VLC system,when the receiver uses maximum likelihood(ML)estimation,the constellation design can be performed by jointly optimizing the constellation points and the decision threshold and minimizing the error probability at the receiving end;In the multi-carrier VLC system,since the receiving end performs symbol decision based on the minimum Euclidean distance(MED)criterion,we also design the constellation based on the maximum MED criterion.The numerical sim-ulation results verify that the SER performance of the constellation design based the proposed scheme is better than that of other traditional constellation designs.The energy-efficient constellation design without the need for extra DC bias un-der the influence of SDN is considered for a multi-user VLC system under visible light channel.In order to combat the influence of SDN,we propose a constellation design scheme based on the Rotated-minimum Euclidean distance(R-MED)criterion;In or-der to achieve optimal constellation design under any signal-to-noise ratio(SNR),we propose a distance range oriented(DRO)constellation design scheme.The numerical simulation results verify that the SER performance of the constellation design based on the R-MED and the DRO criterion is better than the constellation design based on the MED criterion.