Besides illumination, LEDs have been finding applications in data communications due to their fast switching time. As an optical source for shortrange indoor communications, visible LEDs are cheap and reliable, offering high data rate capabilities. An optical wireless communication link using high-brightness illumination LEDs has been demonstrated to support a modulation bandwidth of up to 20 Mb/s [2]. The theoretical background for visible light communication (VLC) systems is similar to that found in infrared (IR) communications except that VLCs use a much wider visible spectrum, as outlined in [3-5]. In addition, we have seen several practical-based high-speed VLCs reported in [6-9]. Through the use of flashlight LEDs, a simplex link and a duplex link combining the two simplex links have also been reported [7].