PULSAR-Net: Neural Reconstruction of LiDAR Point Clouds under Jamming Attacks via Full-Waveform Representation and Simultaneous Laser Sensing

Ryo Yoshida, Takami Sato, Wenlun Zhang, Yuki Hayakawa, Shota Nagai, Kentaro Yoshioka
Keio University
NeurIPS 2026
LiDAR jamming threat model and point cloud reconstruction by PULSAR-Net

Real-world reconstruction under a jamming attack. (i) An attacker injects high-frequency lasers into the victim's LiDAR, and the vehicle ahead disappears from the point cloud. (ii) Without defense, the jammed point cloud (c) contains no vehicles. PULSAR-Net recovers a point cloud (d) that is faithful to the clean one (b), using the intermediate full-waveform representation and the simultaneous sensing feature available in modern LiDARs.

92% / 73% Vehicles reconstructed in real-world static / driving attacks
≥82% Point-level recovery on synthetic benchmarks (≥2× the baseline)
31.7 FPS Inference on an RTX 5090, above the 10–20 FPS perception rate

Abstract

LiDAR sensors are critical for autonomous driving perception, yet remain vulnerable to spoofing attacks. Jamming attacks inject high-frequency laser pulses that completely blind LiDAR sensors by overwhelming authentic returns with malicious signals. We discover that while point clouds become randomized, the underlying full-waveform data retains distinguishable signatures between attack and legitimate signals.

In this work, we propose PULSAR-Net, capable of reconstructing authentic point clouds under jamming attacks by leveraging previously underutilized intermediate full-waveform representations and simultaneous laser sensing in modern LiDAR systems. PULSAR-Net adopts a novel U-Net architecture with axial spatial attention mechanisms specifically designed to identify attack-induced signals from authentic object returns in the full-waveform representation. To address the lack of full-waveform representations in existing LiDAR datasets under jamming attacks, we introduce a physics-aware dataset generation pipeline that synthesizes realistic full-waveform representations under jamming attacks. Despite being trained exclusively on synthetic data, PULSAR-Net achieves reconstruction rates of 92% and 73% for vehicles obscured by jamming attacks in real-world static and driving scenarios, respectively.

Demo on a Real LiDAR Under Attack

A production-ready full-waveform LiDAR, developed with a major LiDAR manufacturer, attacked with the state-of-the-art HFR jamming attack. PULSAR-Net is trained only on synthetic nuScenes-J, with no fine-tuning for this LiDAR.

Demo video. PULSAR-Net against a real LiDAR jamming attack in driving and static scenarios, with CenterPoint detections overlaid. The target vehicle disappears from the jammed point cloud in every frame, and PULSAR-Net recovers it.

Point cloud reconstructed by PULSAR-Net Point cloud without attack or under attack
No Attack PULSAR-Net

Left: No Attack / Under Attack (alternating)  |  Right: PULSAR-Net Reconstruction

Hover or drag to move the slider yourself.

Experimental setup with the full-waveform LiDAR, target vehicle, and jamming device

Experimental setup. Our production-ready full-waveform LiDAR, a target vehicle about 59 m away, and the jamming device.

Real-world mAP across four static and three driving scenarios. Benign data is not available for driving scenarios.
Detector Static (4 scenarios)Driving (3 scenarios)
No AttackNo DefenseOursNo DefenseOurs
PointPillars49.70.1049.80.7050.7
CenterPoint67.10.0069.40.2063.1
PV-RCNN44.00.0049.80.0053.8
  • Static scenarios. Jamming collapses detection to mAP ≈ 0. PULSAR-Net restores it to the no-attack level or slightly above, and reconstructs 91.7% of the vehicles erased by the attack (CenterPoint, IoU 0.4).
  • Driving scenarios (up to 30.5 km/h). PULSAR-Net recovers 50.7 / 63.1 / 53.8 mAP from near zero and reconstructs 73.2% of erased vehicles, showing that the reconstruction keeps enough geometric cues even under motion.

Contributions

  • PULSAR-Net (Point cloud Un-jamming via LiDAR Signal Adaptive Reconstruction), the first successful defense against jamming attacks on LiDAR systems: a U-Net-based architecture with axial spatial attention designed for attack-signal segmentation in the full-waveform representation.
  • A physics-based synthesis pipeline that generates realistic full-waveform data under jamming attacks from existing point cloud datasets (KITTI-J and nuScenes-J).
  • A recovery rate of ≥82% of points obscured by jamming on our synthetic benchmarks, an ≥2-fold improvement over a naive baseline.
  • Integration into a production-ready LiDAR with full-waveform access, developed with a major supplier. Trained solely on simulated data, PULSAR-Net reconstructs 92% and 73% of erased vehicles in real-world static and driving scenarios.

Key Insight: The Legitimate Echo Is Still There

A LiDAR records a waveform (received intensity over time) for every laser shot and keeps only its strongest peak as the point. Jamming hides the real echo behind stronger attack pulses, but does not remove it from the waveform.

Legitimate echo from the object Attack pulse
1No attack
time = distancedetected peak = correct distance

The only peak is the echo, so the measured distance is correct.

2Under attack
echo still heredetected peak = wrong distance

Stronger attack pulses win peak detection and the point lands at a random distance. The echo is still in the waveform.

3Compare receivers fired at the same time
same timing in every receiverRx 1Rx 2Rx 3Rx 4

The jammer’s wide beam hits all receivers at once, so attack pulses line up. Echoes depend on each object and do not.

4PULSAR-Net removes the aligned pulses
time = distancecorrect distance recovered

Peak detection on the cleaned waveform finds the echo again, restoring the correct point.

PULSAR-Net

PULSAR-Net architecture

A U-Net with depthwise-separable 3D convolutions and axial attention labels every waveform sample as attack pulse, legitimate echo, or background. Removing the attack pulses and running peak detection again gives the reconstructed point cloud. Training data is synthesized from KITTI and nuScenes with a physics-aware jamming simulation. See the paper for details.

Results on KITTI-J and nuScenes-J

Synthetic jamming benchmarks with φ = 110 simultaneous sensing lasers. Point-level accuracy counts a point as recovered if it lies within 0.5 m of the clean point. Other φ values and ablations are in the paper.
Method Point-level accuracy (%)Detection mAP
nuScenes-JKITTI-JnuScenes-J
PointPillars
KITTI-J
PV-RCNN
No Defense3.392.820.000.00
Naive Avg. Sub.32.6035.212.5632.94
Neural DSP (ICCV 2025)47.8413.4437.701.43
Ours86.3289.4465.5255.74
No Attack (reference)––69.8762.75

Acknowledgements

We gratefully acknowledge Takahiro Kado, Ibuki Fujioka, and Taro Beppu at Sony Semiconductor Solutions for their generous support and for providing the Sony LiDAR sensor used in this work. The Sony LiDAR system played an essential role in enabling this research.

BibTeX

@inproceedings{yoshida2026pulsarnet,
    author    = {Yoshida, Ryo and Sato, Takami and Zhang, Wenlun and Hayakawa, Yuki and Nagai, Shota and Yoshioka, Kentaro},
    title     = {Neural Reconstruction of {LiDAR} Point Clouds under Jamming Attacks via Full-Waveform Representation and Simultaneous Laser Sensing},
    booktitle = {Advances in Neural Information Processing Systems (NeurIPS)},
    year      = {2026}
}