An application of OFDM-IDMA to uplink multiuser visible light communication system

Wireless visible light communication system uses LED illumination for data transmission. It is important for a performance index to evaluate a variation of communication quality with the number of users. Although CDMA (Code Division Multiple Access) is a representative of a conventional multiple access in a wireless communication, the maximum number of users is limited due to the length of the spread code, ISI (Inter-Symbol Interference) and MAI (Multiple Access Interference). To solve these problems, we propose the OFDM-IDMA (Orthogonal Frequency Division Multiplexing - Interleave Division Multiple Access), which has robustness for the above-mentioned problems. Moreover, we can improve the robustness by using multi carrier modulation. Therefore we apply the OFDM-IDMA system to visible light communication system. The simulation result shows that BER performance of an optical OFDM-IDMA with multiuser situation is the approximately same as that of single user.