白光LED灯几MHz到几百MHz的调制带宽使其在照明的同时兼具通信功能。首先提出了照度均方差最小化准则来设计LED灯在室内的布局问题，分别考虑了不包含墙壁反射和包含墙壁反射两种情况下对室内照度分布的影响，分别给出了两种情况下白光LED灯的最优布局。然后分析了室内视距链路（不包含墙壁反射）和非视距链路（包含墙壁反射）下的室内照度分布、接收功率分布以及信噪比分布。非视距链路相对于视距链路来说，室内照度分布和接收功率分布明显增加，但是信噪比明显下降，这主要是由于非视距链路下墙壁反射产生的码间干扰所致。

LED could be used for both the illumination and the wireless communication simultaneously that owns the modulation bandwidth from several MHz to several hundreds of MHz. The criterion of the minimum mean square deviation was used to design the layout of LED in the room. The indoor illumination distribution was analyzed in the two conditions which were respectively not included the wall reflection and included it. Then the illuminance, the received power for detector and the signal to noise ratio for the line of sight(not including the wall reflection) and the non line of sight(including the wall reflection) were analyzed, respectively. It is concluded that the illuminance and the received power are larger for the non line of sight than the line of sight, but the signal to noise ratio decreases. This is mainly caused by the inter symbol interference from the reflection of the wall of the non line of sight.