Demonstration of an optical wireless communication link with pre‐emphasis circuit for high‐speed application

Abstract

AbstractIn this article, we experimentally demonstrate an optical wireless communication link based on Non‐Return to Zero (NRZ) On‐Off Keying (OOK) modulation with pre‐emphasis circuit for high‐speed application. We propose an economical hardware pre‐emphasis circuit comprise of one operational amplifier and an RC filter stage with a high‐pass frequency response to enhance passband characteristic of optical wireless communication link. The validity of the pre‐emphasis circuit has been demonstrated by using existing fiber optic and optical wireless communication link and components in our laboratory operating at 1550 nm. But the same pre‐emphasis circuit can be used in other wavelength applications including visual light wavelength range via light‐emitting diodes (LED). By using proposed pre‐emphasis circuit, 3 dB bandwidth of optical wireless link can be extended from 225 to 942 MHz (compared to 289 to 469 MHz without pre‐emphasis circuit). We observed the Bit‐Error‐Rate (BER) optical power penalty improvement of 2.5 dB at BER of 2 × 10−3 (forward error correction [FEC] limits) and 3.6 dB improvement at BER of 1 × 10−9, with a data rate of 1.244 Gb/s.