Impact of LED Temperature on the Performance of LiFi Optical Wireless Communication Links

In this paper, we calculate the degradation of an Optical Wireless Communication (OWC) system caused by the junction temperature of the LED. Its throughput depends on the LED frequency response and on the received power versus the noise floor. Thus, the throughput can be calculated from the optimal modulation bandwidth, the efficiency, and the spectral density of the LED, which all are temperature dependent. For an OWC system based on LEDs, the low 3 dB bandwidth limits the achievable throughput of the system. Although, we increase the bandwidth by driving the LED at higher current density, that increases the junction temperature. We explore the effects that temperature has on the dynamic behavior of the LED and subsequently on the SNR and throughput of the OWC link. Our results can be used to optimize the throughput including the effect of self-heating nature of the LED.