Transmitter for 1.9 Gbps phosphor white light visible light communication without a blue filter based on OOK-NRZ...

Area of Science:

• Optical Communications
• Solid-State Lighting

Background:

• Visible light communication (VLC) systems using high-power phosphor-coated LEDs face limitations in bandwidth and slow yellow light emission, hindering high data rates.
• Existing methods to overcome these limitations often involve complex filtering or do not fully address the spectral characteristics of phosphor-coated LEDs.

Purpose of the Study:

• To propose and demonstrate a novel transmitter design for wideband VLC systems utilizing commercial phosphor-coated LEDs.
• To achieve high data rates without the need for a blue filter by effectively managing the bandwidth limitations and slow yellow light response.

Main Methods:

• Development of a novel transmitter incorporating a folded equalization circuit with a new equalization scheme to expand LED bandwidth.
• Integration of a bridge-T equalizer to mitigate the impact of slow yellow light, offering an alternative to blue filters.
• Experimental validation of the proposed transmitter in a VLC system.

Main Results:

• The 3 dB bandwidth of the VLC system was significantly extended from several megahertz to 893 MHz.
• The system successfully supported real-time on-off keying non-return to zero (OOK-NRZ) data rates up to 1.9 Gb/s.
• A low bit error rate (BER) of 3 × 10^-5 was achieved at a transmission distance of 7 meters.

Conclusions:

• The proposed novel transmitter effectively overcomes the bandwidth limitations and slow yellow light issues inherent in phosphor-coated LEDs for VLC.
• This advancement enables high-speed, wideband VLC systems using readily available commercial LEDs without requiring additional blue filters.
• The demonstrated performance paves the way for enhanced VLC applications demanding high data throughput.