Energy Efficiency Analysis of Light-Emitting Diodes With High Modulation Bandwidth

This letter proposes an analytical model on the energy efficiency for visible light communications (VLC) based on light-emitting diode (LED). We certify the variation pattern of energy efficiency of LEDs follows the second-order system rather than the first-order system like the LED's frequency response. This pattern means considerable power loss in the VLC transmission, which should be taken care of when designing VLC systems. This letter demonstrates a series of simulations and experiments to prove this viewpoint's accuracy. Moreover, by comparing the experimental results, we analyze the influence of LED's parasitic parameters on energy efficiency. Furthermore, a linear LED equivalent circuit model is given for the high modulation bandwidth application. We test it by calculating its decisive coefficients according to different LEDs' experimental results.