Performance Evaluation of NRZ-OOK and Carrier-Less Amplitude Phase Modulation in Li-Fi Environment

Abstract

Light Fidelity (Li-Fi) is a wireless technology that utilizes light emitting diodes to convey data. Li-Fi has emerged as a promising alternative to radio frequency communication technology in recent years. This paper examines the performance characterisation between NRZ-OOK and carrier-less amplitude-phase modulation (CAP-2, CAP-4 and CAP-8), within a simulated Li-Fi environment. For the parameters of interest, the eye pattern, bit error rate (BER) and constellation diagram are reported. As no distance is specified in the simulation, the BER for CAP is zero, allowing an ideal transmission to be emulated. The scatter diagram increases as the number of CAP modulations increases. For the eye pattern, CAP modulation provides a better visual representation of how noise might affect system performance compared to OOK modulation.

Analysis of Effect of Input Power and RF Optical Signal Rate on Optical Communication System with OOK-NRZ Modulation

“…Among them is that the resistance to noise is high; this is because the signal cannot be influenced by electromagnetic fields. Another advantage is the signal transmission or bit rate speed, which reaches hundreds of gigabits per second [6].…”

Analysis of Changes in Modulation Parameters on Optical Communication System

“…There is no level change within each bit period; hence, it is called "Non-Return-to-Zero" (NRZ) [3]. On the other hand, OOK modulation is a modulation scheme that discretely changes the optical intensity between two levels, namely "on" (optical signal present) and "off" (optical signal absent) [4,5]. There are several transmission parameters in the NRZ-OOK (On-Off Keying) modulation format, including SpS (Samples per Symbol), Rs (Symbol rate), Pi_dBm (optical signal power at modulator input in dBm), Vπ, and Vb (MZM parameters).…”