Mobile fronthaul solution based on visible light fiber communication and zero-padding 8-D CAP modulation.

Area of Science:

• Optical Communications
• Wireless Networking
• Signal Processing

Background:

• Conventional mobile fronthaul (FH) based on Common Public Radio Interface (CPRI) struggles to meet the demands of 5G technologies like massive multiple-input multiple-output (mMIMO) due to limitations in data rate, bandwidth, and connectivity.
• Visible Light Communication (VLC) is emerging as a promising complementary technology for beyond-5G networks, offering advantages such as unlicensed spectrum, high bandwidth, and cost-effectiveness.
• Existing VLC systems face challenges with low-frequency noise (LFN) in practical deployments.

Purpose of the Study:

• To propose and demonstrate a novel mobile fronthaul solution utilizing Visible Light Fiber Communication (VLFC).
• To introduce an innovative zero-padding N-D carrierless amplitude and phase (CAP) modulation scheme tailored to mitigate LFN in VLFC systems.
• To evaluate the performance of the proposed VLFC system in terms of data rate, channel performance, and wavelength-dependent characteristics.

Main Methods:

• Development of a zero-padding N-D CAP modulation technique, specifically zero-padding 8-D CAP, designed to address LFN in VLFC.
• Implementation of a VLFC system transmitting PAM8 symbols over 100m of multi-mode fiber (MMF) at red (635nm), green (520nm), and blue (488nm) wavelengths.
• Experimental verification of the proposed modulation scheme's effectiveness in enhancing communication performance and achieving similar Bit Error Rate (BER) across multiple channels.

Main Results:

• The zero-padding technique significantly enhances communication performance in the VLFC system.
• All 8 channels demonstrated similar BER performance, indicating effective signal transmission.
• Communication performance improved with longer wavelengths due to reduced attenuation and dispersion in MMF, achieving data rates of 10.8 Gbps (red), 9.0 Gbps (green), and 7.5 Gbps (blue) under the 7% HD-FEC threshold.

Conclusions:

• The proposed zero-padding N-D CAP modulation is an effective solution for mobile fronthaul using VLFC, overcoming LFN challenges.
• The VLFC system offers a viable alternative for future mobile networks requiring high data rates and bandwidth.
• The study highlights the potential of VLC for next-generation communication infrastructure.