White LED offers advantageous properties such as high brightness, reliability, lower power consumption and long lifetime. White LEDs are expected to serve in the next generation of lamps. An indoor visible-light wireless communication system using white LED lightings has been proposed from our laboratory. In the proposed system, these devices are used not only for illuminating rooms but also for a wireless optical communication system. Generally, plural lights are installed in our room. So, their optical path difference must be considered. We discuss about the influence of intersymbol interference and the difference between visible-light wireless communication and other optical wireless communication. Based on numerical analyses, we show that the system will expect as indoor communication of next generation.