Increasing symbol rate by ensemble averaging with dual camera in rolling-shutter optical camera communication

Abstract

Rolling-shutter (RS) optical camera communication (OCC) is effective to increase symbol rate in indoor OCC from LED lamp to smartphones’ built-in camera. However, exposure time of RS camera is longer than the line interval of the camera. Symbol error rate deteriorates as the symbol rate increases owing to inter-symbol interference (ISI). To reduce ISI, dual camera is adapted. Ensemble averaging in number of decision pixels per symbol with dual camera suppresses ISI. Error-free symbol rate was increased with dual camera more than that with a single camera. The reason for increase in symbol rate is elucidated with the correlation coefficient.