Data rate of optical camera communication is limited by low frame rate of the CMOS image sensor, so that multilevel modulation is required to improve its data rate. However, transmission performance may decrease with varying transmission distance between LED and image sensor due to nonlinearity occurred by saturation of received optical power. In this paper, we propose gamma function based signal compensation to overcome the nonlinearity and improve the performance of multilevel transmission. As an experimental demonstration, we transmitted maximum 16 pulse amplitude modulation signal and achieved data rate of 199.78 kb/s and symbol error rate (SER) under using the image sensor of 99.89 kfps with the transmission distance of 250 cm.
Bibliographical noteFunding Information:
Manuscript received March 18, 2018; revised July 10, 2018; accepted July 16, 2018. Date of publication July 25, 2018; date of current version August 7, 2018. This work was supported by Korea Power Corporation, Republic of Korea (R17XA05-67). Corresponding author: Sang-Kook Han (e-mail: firstname.lastname@example.org).
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering