In this paper, we present an indoor positioning system were trichromatic white LEDs are used as transmitters and an optical processor based on a-SiC:H technology as mobile receiver. The optical processor is realized using a double p-i-n photodetector with two UV light biased gates. The relationship between the optical inputs (transmitted data) and the corresponding digital output levels (received data) is established and decoded. The received signal is used in coded multiplexing techniques for supporting communications and navigation concomitantly on the same channel. The position of the device is estimated using the visible multilateration method through the strength of the signal received from several non-collinear transmitters. The location and motion information is found by mapping position and estimates the location areas. Since the indoor position and transmitted data of the different LED light sources is known from building floor plans and lighting plans, the corresponding transmitted data information, indoor position and travel direction of the mobile device can be determined.