FMCW LiDAR Crosstalk Mitigation via Signal Extraction
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Solution Overview
Problem
Coherent LiDAR systems face interference across channels due to crosstalk, leading to 'ghost' targets in the point cloud, which affect range, velocity, and reflectivity measurements.
Innovation Solution
The LiDAR system employs techniques to identify and exclude crosstalk signals by determining their frequency and intensity, using methods such as ignoring frequency bands or applying higher noise limits, to produce corrected signals for accurate target detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple channels are used in the LiDAR system to detect targets, then the coverage and detection capability are improved, but cross-channel interference occurs leading to ghost targets
Solution Approach 1:
The patent extracts and removes crosstalk signals from the detected signal by identifying their characteristic frequency (DC or near-DC) and intensity, then subtracting them from the original signal to produce a corrected signal free from cross-channel interference
Solution Approach 2:
The system uses feedback by monitoring the first channel's signal and using it to predict and compensate for crosstalk in the second channel, continuously adjusting the correction based on the detected crosstalk characteristics
2Measurement precision
If crosstalk compensation techniques are applied, then measurement accuracy is improved, but system complexity increases
Solution Approach 1:
The patent introduces an intermediary processing step that uses the first channel's signal as a mediator to predict and remove crosstalk from the second channel, adding complexity only where interference actually occurs rather than processing all signals uniformly
Data Source
AI summary
A first signal at a first channel and a second signal at a second channel are received at the LiDAR system. A frequency of a crosstalk signal in a detection of the second signal is determined based on the first signal. An intensity of the crosstalk signal is determined based on the intensity of the first signal. Provided the intensity of the crosstalk signal is in a detectable range, the crosstalk signal is excluded from the detection of the second signal to produce a corrected second signal, to extract the at least one of range or velocity information related to a target based on the corrected second signal.