Outdoor environment LED-identification systems integrate STBC-OFDM

In an outdoor environment light emitting diodes-identification (LED-ID) systems, the provision of real-time location information to mobile users has become an active area of research. Visible light communication (VLC) in a LED-ID system offers the promise of a safe, efficient, reliable, and environmentally friendly ID technique. However, there are still several problems associated with such a combination, especially optical multipath dispersion, which has a severe impact on the communication performance. In this paper, we simulated a realistic optical channel in outdoor environment and modeled it as a Rician channel. Based on such a channel model, we further proposed an effective scheme of STBC-OFDM to solve the severe optical multipath dispersion problem and to obtain a target BER of 10^-6 at a low SNR, where the received optical signals suffer from deep optical path loss over a long propagation distance. By comparing the BER performances of STBC-OFDM and SISO, our simulation results demonstrated that the STBC-OFDM technique used in a LED-ID system can alleviate the serious effects of multipath dispersion and can tolerate a low SNR for a target BER of 10^-6.