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Two-stage look-up-table-based 16QAM vector millimeter-wave signal generation and reception
Optics Letters
|February 15, 2024
Summary
A novel two-stage look-up table (LUT) scheme enhances photonic millimeter-wave (MMW) communication. This system improves signal transmission quality and receiver sensitivity, achieving error correction thresholds in free-space optics (FSO) channels.
Area of Science:
- Optical Communications
- Wireless Communication Systems
- Signal Processing
Background:
- Photonic millimeter-wave (MMW) systems offer high bandwidth potential.
- Quadrature Amplitude Modulation (QAM) is crucial for data encoding.
- Free-space optics (FSO) channels face challenges from turbulence and nonlinearities.
Purpose of the Study:
- To introduce a two-stage look-up table (LUT) scheme for photonic 16-QAM MMW systems.
- To enhance signal transmission performance and receiver sensitivity.
- To mitigate channel impairments in FSO communication.
Main Methods:
- Implemented a transmitter-side LUT for adaptive amplitude adjustment, eliminating complex computations.
- Utilized a receiver-side LUT for nonlinear post-compensation of channel distortions.
- Evaluated system performance using bit error ratio (BER) and forward error correction (FEC) thresholds.
Main Results:
- Achieved signal transmission below the HD-FEC threshold (3.8 × 10-3) at 2/4 GBaud (weak turbulence) and 2 GBaud (medium turbulence) in FSO channels.
- Improved optical receiver sensitivity by 0.15 dB at 2 GBaud (medium turbulence) using the second-stage LUT.
- Enabled the system to reach the SD-FEC threshold (4.2 × 10-2) at 4 GBaud with the second-stage LUT.
Conclusions:
- The proposed two-stage LUT scheme effectively enhances photonic 16-QAM MMW communication performance.
- The system demonstrates robustness against channel turbulence and nonlinearities.
- This approach offers a viable solution for improving data rates and reliability in FSO systems.
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