Experimental Demonstration of Non-Line-of-Sight MIMO Optical Camera Communications with DBPWR Algorithm

In this work, we propose a multiple inputs multiple outputs (MIMO) non-line-of-sight (NLOS) optical camera communication (OCC) system with multi-level pulse width modulation (MPWM) and difference-based pulse width recognition (DBPWR) schemes. The MPWM signals transmitted over a NLOS link are recovered using the DBPWR algorithm. Compared with the conventional threshold-based demodulation scheme, the proposed DBPWR scheme has lower complexity, higher reliability, and improved sampling frequency offset tolerance. A total data rate of 3.6 kb/s is experimentally demonstrated for more than 2 m NLOS link using the proposed MIMO OCC system, which is sufficient in many Internet of things applications.