This paper experimentally demonstrates that the AC impedance spectrum of the LED as a photodetector heavily depends on the received optical power, which may cause the impedance mismatch between the LED and the post trans-impedance amplifier. The optical power dependent impedance of the LED is well fitted by a modified dispersive carrier transport model for inorganic semiconductors. The bandwidth of the LED-LED visible light communication link is further shown to decrease with the optical power received by the LED. This leads to a trade-off between link bandwidth and SNR, and consequently affects the choice of the proper dada modulation scheme.
@article{arxiv.1709.05921,
title = {LED receiver impedance and its effects on LED-LED visible light communications},
author = {Shangbin Li and Boyang Huang and Zhengyuan Xu},
journal= {arXiv preprint arXiv:1709.05921},
year = {2017}
}