Space-time multichannel adaptive filtering scheme for VLC color cross-talk equalization.

Area of Science:

• Optical Communications
• Signal Processing

Background:

• Visible light communication (VLC) systems face bandwidth limitations with traditional light-emitting diodes (LEDs).
• Red-green-blue (RGB) LEDs offer higher modulation bandwidth and enable spatial multiplexing for parallel data channels.
• RGB-tuned photodiodes (PDs) are used at the receiver, but suffer from color crosstalk, limiting spectral efficiency.

Purpose of the Study:

• To investigate spatial (color) interference in RGB LED-based VLC systems using amplitude shift keying (ASK) modulation.
• To develop and analyze a blind multichannel adaptive equalizer for mitigating intersymbol interference (ISI) and spatial interference.
• To evaluate the convergence and performance of the proposed adaptive algorithm.

Main Methods:

• Utilizing RGB LEDs as transmitters and RGB-tuned PDs as receivers.
• Implementing amplitude shift keying (ASK) modulation.
• Developing a blind multichannel adaptive equalizer to counteract both temporary ISI and spatial (color) ISI.
• Employing color filters to partially suppress spatial interference.

Main Results:

• The proposed blind multichannel adaptive equalizer effectively mitigates both intersymbol interference (ISI) and spatial (color) interference.
• Analysis of the adaptive algorithm's convergence properties was performed.
• Performance comparison with existing literature demonstrated the equalizer's efficacy.

Conclusions:

• A novel blind adaptive equalizer successfully addresses crosstalk in RGB LED-based VLC systems.
• The developed method enhances spectral efficiency by mitigating spatial interference.
• This approach offers a viable solution for improving the reliability of visible light communication systems.