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Beat signal enhancement algorithm for frequency modulated continuous wave lidar based on phase reversal and frequency
Optics Express
|August 13, 2025
Summary
This study introduces a phase reversal frequency complementary method to boost weak beat frequency signals in long-distance detection. The technique enhances signal energy and improves signal-to-noise ratios (SNRs) by 5-10 dB.
Area of Science:
- Optics
- Signal Processing
Background:
- Long-distance detection suffers from weak beat frequency amplitude.
- Useless beat frequency spectrum occupies signal energy.
Purpose of the Study:
- To propose a novel frequency complementary method based on phase reversal.
- To enhance beat signal energy and improve signal-to-noise ratios (SNRs).
Main Methods:
- Converting local reference and reflected signals to complex signals.
- Generating opposite phase signs between up-ramp and down-ramp segments.
- Relocating sum-frequency to beat frequency position using time-frequency complementarity.
Main Results:
- The proposed method enhances beat signal energy.
- Achieved stronger beat signal energy in the 50 m to 350 m detection range.
- All SNRs were higher than the conventional method by 5-10 dB.
Conclusions:
- The phase reversal frequency complementary method effectively addresses weak amplitude and energy occupation issues.
- The novel method offers significant improvements in signal detection over conventional techniques.
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