Bandwidth enhancement with DAC-enabled pre-equalization and real-valued precoding for a FBMC-VLC.
Optics Letters
|September 15, 2022
Summary
This study introduces a hybrid scheme using a radio frequency digital-to-analog converter for pre-equalization and real-valued precoding to boost visible light communication (VLC) systems. The method significantly enhances modulation bandwidth and net bit rate, overcoming limitations in LED-based VLC.
Area of Science:
- Optical Communications
- Wireless Networks
- Signal Processing
Background:
- Modulation bandwidth limitation hinders data rates in visible light communication (VLC) systems.
- Existing solutions involve complex digital/analog pre-equalization or adaptive modulation.
- Light-emitting diode (LED)-based VLC faces inherent bandwidth constraints.
Purpose of the Study:
- To propose and experimentally validate a hybrid scheme for enhancing VLC system performance.
- To overcome modulation bandwidth limitations without complex signal processing.
- To improve data transmission rates in spectral-efficient filter bank multi-carrier (FBMC)-based VLC.
Main Methods:
- Utilizing a radio frequency (RF) digital-to-analog converter (DAC) for direct signal pre-equalization.
- Applying low-complexity real-valued precoding techniques for peak-to-average power ratio (PAPR) reduction and subcarrier signal-to-noise ratio (SNR) equalization.
- Experimentally investigating the hybrid scheme in a spectral-efficient FBMC-based VLC transmission system.
Main Results:
- PAPR reduction exceeding 3 dB at a complementary cumulative distribution function of 1 × 10-4 achieved with real-valued precoding.
- Modulation bandwidth increased to 515 MHz for 16-quadrature amplitude modulation (QAM)-FBMC.
- Achieved a bit error rate below 3.8 × 10-3 over 2.3-m free-space transmission.
- Net bit rate improvement of over 45% compared to conventional FBMC-VLC.
Conclusions:
- The proposed hybrid scheme effectively enhances modulation bandwidth and data rates in VLC systems.
- Direct pre-equalization via RF-DAC and real-valued precoding offer a simplified yet powerful solution.
- This approach presents a significant advancement for practical FBMC-VLC applications.
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