Research On Light Source Layout Optimization In Visible Light Body Area Network

The existing visible light communication(VLC)and body area network(BAN)are mostly independent research,while the cross-research of VLC and BAN is seldom and mostly about the shadow effect brought by the human body in VLC.The visible light body area network,research that regards the human body as a part of the VLC system,is scarce.In classical VLC research,light source layout is a popular and important research field,which requires good communication under the premise of ensuring normal lighting.A good light source layout will directly determine the performance upper bound of the communication system.Therefore,this paper chooses to research the optimization of light source layout in visible light body area network,and carries out the following work:(1)The whole process of visible light body area network communication modeling is explained.Starting from the physical background,this paper gives a comprehensive description of the light source,reflection,noise,simulation algorithm and system indicators involved in visible light body area network modeling.Each part not only describes what will be used later,but also the mainstream in each part of the existing VLC simulation is introduced.(2)Human factors in visible light body area network are modeled.The human body was modeled based on "Human dimensions of Chinese adults",and four typical locations were selected as the location of the receiver.Based on the equal probability random walk model,the orientation and position model of a human without purpose in the room is calculated,and the corresponding weight of orientation and position is obtained.Using the enveloping box to abstract description of human body shape,the relation between the human body and light is simplified to the relation between the box and light,and the specific mathematical method is expounded.(3)Joint optimization of light source layout and data.In the existing VLC light source layout optimization,one is to optimize the light source data with fixed light source layout,the other is to optimize the light source layout with fixed light source data.The former changes the total luminous flux or power,so it is not rigorous to conduct a horizontal comparison of system performance,while the latter only considers the influence of layout without considering the influence of the choice of light source data on the overall system performance.In this paper,under the fixed total luminous flux and optical power,the light source data and layout are optimized jointly,and the optimal light source layout is found within the set layout model framework.(4)In this paper,four different positions on the body are selected to place the receivers,then the optimized light source layout corresponding to each position is obtained through the optimization algorithm,next the receiver performance at four positions under each layout is analyzed.In conclusion,the top of head is not suitable for the placement of the receiver.For the wrist,abdomen and chest position of the receiver,the best light source layout corresponding to the abdominal position of the receiver should be selected as the light source layout.In summary,VLC and BAN are further integrated in this paper,and the human factor model of visible light body area network is preliminarily established.Some optional receiver positions and the corresponding optimized light source layout are determined,which provides a reference for further research in this field.