Research

Research directions and publications. My name is highlighted.

2025 – now

Robust reconstruction for unlimited sampling

Modulo ADCs fold high-dynamic-range signals into a bounded range, and classical unfolding breaks down when the threshold, sampling density or signal model is mismatched. I build reconstruction methods that stay reliable — a multi-output network with a physics-based refinement (6× lower NMSE than the best classical method on a mixed benchmark), integer-aware OMP for compressive unlimited sampling, and a systematic robustness study for radar signals.

2024 – 2025

Diffusion models for molecule generation

A hierarchical diffusion model that denoises scaffold atoms before substituents, with an EGNN that also predicts each atom's role and time-gated classifier guidance — 91.7% molecular stability on QM9 and markedly faster convergence than EDM.

2025 – 2026

Language models from scratch

Self-study of Stanford CS336: a byte-level BPE tokenizer and Transformer LM written from scratch, Chinchilla-style scaling-law fitting, a Common Crawl filtering and deduplication pipeline, and SFT/GRPO on Qwen2.5-Math-1.5B that raised MATH accuracy to 63%.

2018 – 2023

Wireless networks and federated learning

At Tsinghua, delay analysis of wireless federated learning with saddle-point approximation and large deviation theory, and popularity prediction for edge caching. At Huawei, wireless localization and base-station parameter calibration that replaced manual drive tests in a commercial platform.

Publications & Patents

2026

Robust Neural Reconstruction for Unlimited Sampling

Longwei Yang, Ali C. Gurbuz, Fauzia Ahmad

Submitted to IEEE Transactions on Signal Processing, 2026

TSPUnder review

Compressive Unlimited Sampling with Smooth-Coded Measurements and Integer-Aware OMP

Longwei Yang, Ali C. Gurbuz, Fauzia Ahmad

Submitted to IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2027), 2026

ICASSPUnder review

On the Robustness of Unlimited Sampling: An Empirical Study

Longwei Yang, Ali C. Gurbuz, Fauzia Ahmad

IEEE Radar Conference (RadarConf'26), 2026

RadarConf 2026Paper

2025

Scaffold–Substituent Differentiated Diffusion for Hierarchical Molecule Generation

Longwei Yang, et al.

Manuscript, 2025

Manuscript

2021

Delay Analysis of Wireless Federated Learning Based on Saddle Point Approximation and Large Deviation Theory

Lintao Li, Longwei Yang, Xin Guo, Yuanming Shi, Haiming Wang, Wei Chen, Khaled B. Letaief

IEEE Journal on Selected Areas in Communications, 2021

JSAC 2021Paper

Method and Apparatus for Controlling Content Caching in Edge Computing System

Wei Chen, Zhanyuan Xie, Zhiyuan Lin, Longwei Yang, Xin Guo, Haiming Wang

PCT Patent WO2021159304A1, published Aug 2021, 2021

Patent 2021Paper

Saddle Point Approximation Based Delay Analysis for Wireless Federated Learning

Longwei Yang, Lintao Li, Xin Guo, Yuanming Shi, Haiming Wang, Wei Chen

IEEE International Conference on Communications (ICC), 2021

ICC 2021Paper

2020

A Video Popularity Prediction Scheme with Attention-Based LSTM and Feature Embedding

Longwei Yang, Xin Guo, Haiming Wang, Wei Chen

IEEE Global Communications Conference (GLOBECOM), 2020

GLOBECOM 2020Paper
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