Low complexity of optical filter bank multi-carrier (FBMC) modulation for visible light communication using laser diode

• Main Author: Qasim, Abdullah Ali
• Format: Thesis
• Language: English; English; English
• Published: 2022
• Subjects: TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.uthm.edu.my/8375/1/24p%20ABDULLAH%20ALI%20QASIM.pdf; http://eprints.uthm.edu.my/8375/2/ABDULLAH%20ALI%20QASIM%20COPYRIGHT%20DECLARATION.pdf; http://eprints.uthm.edu.my/8375/3/ABDULLAH%20ALI%20QASIM%20WATERMARK.pdf; http://eprints.uthm.edu.my/8375/

DC-bias Optical Filter Bank Multi-carrier (DCO-FBMC) was used as a modulation technology compatible with Intensity Modulation/Direct Detection (IM/DD) that will provide a high data rate for visible light communication (VLC). The DCO-FBMC modulation is one of the most effective modulation techniques, but power consumption is the obstacle facing the current development. The FBMC modulation deals with Hermitian Symmetry to generate a real signal, which leads to higher power consumption. As well modelling the distribution of luminaires in VLC is challenging in terms of dark spots (especially in the middle and at the edges of the room), besides higher power consumption. Therefore, problem of using Hermitian symmetry was addressed using the complex signal out of the traditional FBMC modulation in the time domain by separating the signal’s real part from the complex signal. As a result, the real and imaginary parts are aligned, thus gaining a real FBMC signal. This proposed technique reduces complexity by 57%, leading to a reduction in power consumption. In addition, a unipolar technique was also proposed to treat the power consumption resulting from the use of DC bias, called Flip-FBMC. This method separates the positive part of the real FBMC signal from the negative part and then inverting and merging it with the positive part. Thus, a unipolar signal is obtained without using DC bias. To address the problem of illumination distribution, a laser diode (LD) was used in two proposed scenarios, where scenario 2 was designed using five luminaires, while scenario 3 was designed with 13 luminaires using the optical FBMC modulation technique. The optimal semi-angle and FOV for each scenario improved the illumination distribution, power and SNR distribution. As a result, the power consumption was reduced by 13.1944% for scenario 2 and 18.75% for scenario 3, respectively, compared to the previous scenarios.