Gigabit polarization division multiplexing in visible light communication

Area of Science:

• Optical Communications
• Wireless Technologies
• Photonics

Background:

• Visible light communication (VLC) systems offer a promising alternative for high-speed wireless data transmission.
• Traditional VLC systems face limitations in spectral efficiency and data capacity.
• Polarization Division Multiplexing (PDM) is a technique used in optical fiber communications to increase data rates.

Purpose of the Study:

• To propose and experimentally demonstrate polarization division multiplexing (PDM) for the first time in visible light communication (VLC) systems.
• To achieve high spectral efficiency and aggregate data rates using PDM with incoherent light-emitting diodes (LEDs).
• To analyze the performance and crosstalk characteristics of the PDM-based VLC system.

Main Methods:

• Implementation of PDM using two orthogonal groups of linear polarizers with incoherent LEDs.
• Employment of spectrally efficient 16-ary quadrature amplitude modulation (16-QAM) Nyquist single-carrier frequency domain equalization (SC-FDE).
• Experimental setup for 80 cm free-space transmission to measure data rates and bit error rates (BER).

Main Results:

• Demonstration of PDM in a VLC system, achieving an aggregate data rate of 1 Gb/s.
• BER results for both polarization directions were below the 7% pre-forward-error-correction threshold of 3.8×10⁻³.
• Analysis of crosstalk between orthogonal polarizations (x and y) was performed.

Conclusions:

• PDM is a viable technique for significantly enhancing data rates in VLC systems.
• The proposed system achieves high spectral efficiency and reliable data transmission over short-range free-space links.
• Further investigation into crosstalk mitigation can lead to even higher performance in future VLC applications.