面向下一代雷达的波形设计：智能、博弈与学习

雷达波形设计是提升雷达系统感知性能的核心。本研究旨在探索基于智能优化、博弈论与元学习等前沿理论的新一代波形设计方法，致力于解决复杂电磁环境下波形在分辨率、模糊度与稳健性之间的根本权衡难题，以显著增强雷达等主动感知系统在目标探测、精密跟踪与特征识别等方面的能力。

如图所示，波形设计的本质，是在软硬件条件与实际应用所构成的多维约束下，于高维参数空间中稳定且高效地寻找最优或次优波形。无论是基于解析的代数方法、基于模型的优化理论，还是基于数据驱动的学习方法，均在此统一框架下探索特有的设计路径与性能边界。

通过构建融合智能决策、博弈交互与元学习能力的波形设计新框架，本研究方向致力于为实现自适应、认知化与协同化的下一代雷达系统提供坚实的理论支撑与关键技术。

感知通信一体化：智能波形、协同感知与跨层优化

感知通信一体化是构建下一代无线通信系统的核心范式，旨在通过统一的信号与资源实现通信与感知功能的深度融合与性能倍增。本研究聚焦于智能波形设计、多站协同感知与跨层资源优化三个关键层次，致力于解决通感频谱共享、性能权衡与系统适配等根本性挑战。

具体而言，研究贯通从物理层到网络层的技术链条：以智能波形为物理层基础，确保信号在通信速率与感知精度间的内在兼容；通过智能反射面、分布式节点等多站协同架构，突破单站感知在覆盖与精度上的局限；最终，依托跨层动态资源调度，将感知任务的不确定性、信道状态与网络负载统一建模，实现系统整体效能的全局最优。

通过构建“信号-架构-系统”一体化的通感设计新框架，本研究为实现高可靠、低延迟与高精度的6G全域智能网络提供理论基石与关键技术。

可重构电磁环境：智能表面与动态阵列

可重构电磁环境是提升无线感知与通信系统性能的革命性途径，其核心在于通过智能表面与动态阵列对传播信道与辐射特性进行主动调控。本研究旨在探索可重构智能表面与流体天线等新型可重构天线阵列在无线感知中的基础理论与关键技术，致力于解决传统系统在覆盖盲区、多径衰落与视角受限等方面的固有瓶颈。

具体而言，研究涵盖从被动反射到主动辐射的全维度重构：利用智能表面动态塑造无线信道，增强感知信号的强度、多样性及覆盖范围；通过流体天线等动态阵列实时优化辐射特性，实现更为精准与敏捷的波束指向与模式切换。

通过构建“信道-阵列”一体化的协同感知新范式，本研究方向旨在为实现高鲁棒、自适应与智能化的下一代无线感知系统提供理论与技术支撑。

分布式感知定位：合成孔径、最优部署、资源分配

分布式感知定位通过多节点协同与网络化处理，致力于在复杂环境中实现超越单站能力的高精度、高鲁棒性目标定位与跟踪，典型代表如分布式合成孔径雷达。本研究聚焦于构建理论严谨、工程可行的分布式感知系统，核心围绕网络化合成孔径成像、传感器网络的最优部署与异构资源动态调度三个层面展开，旨在解决定位精度、系统成本与网络能效之间的根本矛盾。

具体的，利用分布式节点构造虚拟合成孔径，以突破物理孔径极限，实现远距离高分辨率成像；基于克拉美罗界等理论工具，建立传感器位置、类型与数量的优化模型，实现感知精度与部署成本的最优权衡；面向动态跟踪任务的跨节点频谱、功率与计算资源分配，确保系统整体性能最优。

通过建立“节点部署-信号处理-资源调度”一体化的协同感知新范式，本研究为未来大规模物联网及低空经济等场景下的高可靠感知定位提供核心理论与系统支撑。

Book Chapters

● L. Wu and D. P. Palomar,“Cognition-enabled waveform design for ambiguity function shaping,”in Next Generation Cognitive Radar Systems, Ch. 6, K. V. Mishra, B. Shankar M.R., and M. Rangaswamy, The Institution of Engineering and Technology, 2023.

● L. Wu and D. P. Palomar,“Radar Waveform Design via Majorization Minimization,”in Radar Waveform Design based on Optimization Theory, Ch. 7, G. Cui, A. DeMaio, A. Farina, and J. Li, The Institution of Engineering and Technology, 2020.

Journal Papers (* indicates corresponding author, students worked with me are underlined)

● Z. Cheng, L. Wu*, Y. Li, B. Shankar and H. Li,“Two Birds, One Stone: A Per-Frame Approach for Joint Channel Estimation and Target Tracking in HBF-DFRC Systems,”IEEE Transactions on Communications, vol. 73, no. 11, pp. 12294-12309, Nov. 2025.

● S. Xu, L. Wu, X. Li, X. Wu and T. Xu,“AOA Sensor Placement for Anchor-Assisted Target Localization in GNSS-Denied Environment: Formulation, Bounds and Optimization,”IEEE Transactions on Mobile Computing, vol. 24, no. 10, pp. 10792-10806, Oct. 2025.

● S. Xu, L. Wu*, K. Dogancay, M. R. B. Shankar, K. C. Ho and X. Wu,“Optimal Sensor Placement for Target Localization in IoT Systems: A Cramér-Rao Bound Perspective,”in IEEE Internet of Things Magazine, vol. 8, no. 5, pp. 120-126, Sept. 2025.

● Y. Liu, L. Wu*, X. Cai, and B. Shankar,“Graph-Based Multi-Bounce Modeling and Channel Parameter Estimation for Indoor Sensing,”IEEE Transactions on Wireless Communications, vol. 24, no. 5, pp. 4219-4234, May 2025.

● X. Feng, Z. Zhao, H. Huang, L. Wu, Z. Zhao,“Sidelobe Suppression with Low Peak-to-Valley Power Ratio Waveforms in MIMO-OFDM Dual-Function Radar-Communication Systems,”IEEE Transactions on Vehicular Technology, vol. 74, no. 4, pp. 5928-5940, April 2025.

● H. Huang, M. F. Keskin, H. Wymeersch, X. Cai, L. Wu*, J. Thunberg, and F. Tufvesson,“Hybrid Precoder Design for Angle-of-Departure Estimation with Limited-Resolution Phase Shifters,”IEEE Transactions on Communications, vol. 73, no. 6, pp. 4439-4453, June 2025.

● Z. Xie, L. Wu*, X. Huang, C. Fan, J. Zhu, and W. Liu,“Cross Ambiguity Function Shaping of Cognitive MIMO Radar: A Synergistic Approach to Antenna Placement and Waveform Design,”IEEE Transactions on Geoscience and Remote Sensing, vol. 62, pp. 1-13, 2024.

● T. Wei, L. Wu*, K. V. Mishra, and B. Shankar,“RIS-Aided Wideband Holographic DFRC,”IEEE Transactions on Aerospace and Electronic Systems, vol. 60, no. 4, pp. 4241-4256, Aug. 2024.

● Z. Xie, L. Wu*, J. Zhu, M. Lops, X. Huang, and B. Shankar,“RIS-Aided Radar for Target Detection: Clutter Region Analysis and Joint Active-Passive Design,”IEEE Transactions on Signal Processing, vol. 72, pp. 1706-1723, 2024.

● X. Feng, L. Wu, Y. Zhao, Z. Zhao, K. Diao, and M. Soltanalian,“Recurrent Waveform Optimization for Desired Range-Doppler Profile With Low Probability of Interception: A Particle Filter Approach,”IEEE Transactions on Aerospace and Electronic Systems, vol. 60, no. 2, pp. 1899-1911, April 2024.

● T. Wei, L. Wu*, K. V. Mishra, and B. Shankar,“Multi-IRS-Aided Doppler-Tolerant Wideband DFRC System,”IEEE Transactions on Communications, vol. 71, no. 11, pp. 6561-6577, Nov. 2023.

● L. Wu, N. Sahu, S. Xu, P. Babu, and D. Ciuonzo,“Optimization Based Sensor Placement for Multi-Target Localization with Coupling Sensor Clusters,”IEEE Transactions on Signal Processing and Information Processing over Networks, vol. 9, pp. 596-611, 2023.

● M. Alaee-Kerahroodi, L. Wu, E. Raei, and B. Shankar,“Improving Precipitation Estimation via Joint Transmit-Receive Design for Solid State Weather Radar Systems,”IEEE Transactions on Radar Systems, vol. 1, pp. 212-229, 2023.

● L. Wu, X. Cheng, H. Huang, D. Ciuonzo, and B. Shankar,“Constant-Modulus Waveform Design with Polarization-Adaptive Power Allocation in Polarimetric Radar,”IEEE Transactions on Signal Processing, vol. 71, pp. 2146-2161, 2023.

● H. Huang, L. Wu*, B. Shankar, and A. M. Zoubir,“Sparse Array Design for Dual-Function Radar-Communications System,”IEEE Communications Letters, vol. 27, no. 5, pp. 1412-1416, May 2023.

● Z. Cheng, L. Wu*, J. An, and Z. He,“Relative Entropy Based Constant-Envelope Beamforming for Target Detection in Large-Scale MIMO Radar With Low Resolution ADCs,”IEEE Transactions on Vehicular Technology, vol. 72, no. 8, pp. 10090-10106, Aug. 2023.

● X. Cheng, L. Wu, D. Ciuonzo, and W. Wang,“Joint Design of Horizontal and Vertical Polarization Waveforms for Polarimetric Radar Via SINR Maximization,”IEEE Transactions on Aerospace and Electronic Systems, vol. 59, no. 3, pp. 3313-3328, June 2023.

● Z. Cheng, L. Wu*, B. Wang, B. Shankar, and B. Ottersten,“Double-Phase-Shifter based Hybrid Beamforming for mmWave DFRC in the Presence of Extended Target and Clutters,”IEEE Transactions on Wireless Communications, vol. 22, no. 6, pp. 3671-3686, June 2023.

● L. Chen, V. N. Ha, E. Lagunas, L. Wu, S. Chatzinotas, and B. Ottersten,“The Next Generation of Beam Hopping Satellite Systems: Dynamic Beam Illumination with Selective Precoding,”IEEE Transactions on Wireless Communications, vol. 22, no. 4, pp. 2666-2682, April 2023.

● B. Wang, L. Wu, Z. Cheng, and Z. He,“Exploiting Constructive Interference in Non-linear Symbol Level Hybrid Beamforming for Dual-Function Radar-Communication System,”IEEE Wireless Communications Letters, vol. 11, no. 10, pp. 2071-2075, Oct. 2022.

● M. Deng, Z. Cheng, L. Wu, B. Shankar, and Z. He,“One-Bit ADCs/DACs based MIMO Radar: Performance Analysis and Joint Design,”IEEE Transactions on Signal Processing, vol. 70, pp. 2609-2624, 2022.

● S. Xu, L. Wu*, K. Doğançay, and M. Alaee-Kerahroodi,“A Hybrid Approach to Optimal TOA-Sensor Placement with Shared Sensors for Simultaneous Multi-Target Localization,”IEEE Transactions on Signal Processing, vol. 70, pp. 1197-1212, 2022.

● T. Wei, L. Wu*, and B. Shankar,“Joint Waveform and Precoding Design for Joint Radar-Communication SINR Optimization,” IET Signal Processing, vol. 16(7), pp. 788–799, 2022. 

● L. Wu*, K. V. Mishra, B. Shankar, and B. Ottersten,“Resource Allocation in Heterogeneously-Distributed Joint Radar-Communications under Asynchronous Bayesian Tracking Framework,”IEEE Journal of Selected Areas in Communications, vol. 40, no. 7, pp. 2026-2042, July 2022.

● N. Sahu, L. Wu*, P. Babu, B. Shankar, and B. Ottersten,“Optimal sensor placement for source localization: A unified ADMM approach,”IEEE Transactions on Vehicular Technology, vol. 71, no. 4, pp. 4359-4372, April 2022.

● R. Zhou, L. Wu*, and R. S. Cheng,“Energy-Efficiency-Oriented Charge Scheduling and Beamforming for a Two-Tier Wireless Powered Network,”IEEE Internet of Things Journal, vol. 7, no. 3, pp. 2212-2222, Dec. 2019.

● L. Wu*, Y. Feng, and D. P. Palomar,“General Sparse Risk Parity Portfolio Design via Successive Convex Optimization,”Signal Processing, vol. 170, pp. 1-13, Dec. 2019.

● L. Wu* and D. P. Palomar,“Sequence Design for Spectral Shaping via Minimization of Regularized Spectral Level Ratio,”IEEE Transactions on Signal Processing, vol. 67, no. 18, pp. 4683-4695, Sep. 2019.

● L. Wu*, P. Babu, and D. P. Palomar,“Transmit Waveform/Receive Filter Design for MIMO Radar with Multiple Waveform Constraints,”IEEE Transactions on Signal Processing, vol. 66, no. 6, pp. 1526-1540, Mar. 2018.

● L. Wu*, P. Babu, and D. P. Palomar,“Cognitive Radar-Based Sequence Design via SINR Maximization,”IEEE Transactions on Signal Processing, vol. 65, no. 3, pp. 779-793, Feb. 2017.

Conference Papers (students worked with me are underlined)

● Z. Xiao, L. Wu, M. R. Bhavani Shankar and B. Ottersten, "RIS-Enabled Self-Interference Cancellation in Monostatic OFDM-ISAC," 2025 IEEE Radar Conference (RadarConf25), Krakow, Poland, 2025

● K. Zhong et al., "RIS-Aided MIMO Radar Beampattern Matching," 2025 IEEE Radar Conference (RadarConf25), Krakow, Poland, 2025

● D. An et al., "Movable Antenna Aided Hybrid Beamforming for Wideband MIMO Radar Sensing,"2025 IEEE Radar Conference (RadarConf25), Krakow, Poland, 2025

● D. Saha, A. E. Olk, L. Wu, M. Ahmadi and M. R. B. Shankar, "NLoS Radar Sensing for Breathing Rate Estimation in Indoor Environments: An Experimental Study," 2025 IEEE Radar Conference (RadarConf25), Krakow, Poland, 2025

● T. Wei, K. Mishra, L. Wu, and B. Shankar,“Wideband Beamforming with Frequency-Spatial Coupling in Near-Field Holographic ISAC,”in the 33rd European Signal Processing Conference (EUSIPCO), Palermo, Italy, 2025.

● Z. Yang, L. Wu, and Z. Zhao,“Mutual Information Maximization for MIMO Waveform Design Using Minorization-Maximization,”in the 33rd European Signal Processing Conference (EUSIPCO), Palermo, Italy, 2025.

● Y. Liu, L. Wu, X. Cai, and B. Shankar,“Environment Reconstruction in Multi-Bounce Channels with Array Partial Blockage,”in the 33rd European Signal Processing Conference (EUSIPCO), Palermo, Italy, 2025.

● T. Wei, K. V. Mishra, L. Wu, and B. Shankar,“Cramér-Rao bounds for wideband near-field sensing,”in IEEE Int. Conf. Acoust., Speech, Signal Process. (ICASSP), Hyderabad, India, 2025.

● L. Wu, Z. Xiao, B. Shankar, and B. Ottersten,“RIS-enabled self-interference elimination in monostatic full-duplex DFRC systems,”in IEEE Int. Conf. Acoust., Speech, Signal Process. (ICASSP), Hyderabad, India, 2025.

● D. Ciuonzo, A. Zappone, M. Di Renzo, and L. Wu,“Massive MIMO channel-aware decision fusion aided by reconfigurable intelligent surfaces,”in /IEEE Int. Conf. Acoust., Speech, Signal Process. (ICASSP), Hyderabad, India, 2025.

● K. P. Rajput, L. Wu, B. Shankar, B. Ottersten, and P. Varshney,“Tracking time-varying parameters in massive MIMO IoT networks: A linear coherent decentralized approach,”in IEEE Int. Conf. Acoust., Speech, Signal Process. (ICASSP)/, Hyderabad, India, 2025.

● R. Amar, L. Wu, S. Sedighi, M. Alaee, and B. Shankar,“Dual-function waveform design in wireless sensor networks via SoS optimization,”in IEEE Int. Conf. Acoust., Speech, Signal Process. (ICASSP), Hyderabad, India, 2025.

● D. Saha, A. E. Olk, L. Wu and B. Shankar,“Broadband Design of Reflective Multi-Resonator Metasurface for V-Band Applications,”18th International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials), Chania, Greece, 2024

● L. Wu, W. Liu, B. Shankar and B. Ottersten,“Enhanced Jamming Suppression in Colocated MIMO Radar with Fluid Antenna Array,”in Proc. IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM), Corvallis, USA, Jul. 2024.

● K. P. Rajput, L. Wu, B. Shankar and P. K. Varshney,“Joint Transmit Precoders and Passive Reflection Beamformer Design in IRS-Aided IoT Networks,”in Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Seoul, Korea, Republic of, 2024.

● Y. Liu, M. R. Bhavani Shankar, L. Wu and B. Ottersten,“Debris Sensing Based on LEO Constellation: An Intersatellite Channel Parameter Estimation Approach,”in Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Seoul, Korea, Republic of, 2024.

● Y. Yao, F. Shu, L. Wu, X. Cheng, X. Li and J. Wang,“Anti-Jamming Strategy for IRS-Aided JRC System in Vehicular Networks,”in Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Seoul, Korea, Republic of, 2024.

● M. Ahmadi, M. Alaee-Kerahroodi, L. Wu, B. Shankar and B. Ottersten,“Detector Design for Distributed Multichannel Radar Sensors in Colored Interference Environments,”in Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Seoul, Korea, Republic of, 2024.

● Y. Liu, W. Long, R. Chen, L. Wu, and B. Shankar,“Vortex Wavefront FMCW ISAC Model: A Blender-Based Evaluation,”in Proc. IEEE 24th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Shanghai, China, 2023.

● L. Wu, K. P. Rajput, Y. Liu, and B. Shankar,“Distributed Sensing and Centric Computing via FMCW Waveform in Wireless Sensor Network,”in Proc. IEEE 24th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Shanghai, China, 2023.

● K. P. Rajput, L. Wu, and B. Shankar,“Next-Generation IoT Networks: Integrated Sensing Communication and Computation,”in Proc. IEEE 48th International Conference on Acoustics, Speech and Signal Processing (ICASSP), Rhodes, Greece, Jun. 2023.

● L. Wu, B. Wang, Z. Cheng, B. Shankar M. R., and B. Ottersten,“Joint Symbol-Level Precoding and Sub-Block-Level RIS Design for Dual-Function Radar-Communications,”in Proc. IEEE 48th International Conference on Acoustics, Speech and Signal Processing (ICASSP), Rhodes, Greece, Jun. 2023.

● T. Wei, L. Wu, K. V. Mishra, and B. Shankar M. R.,“RIS-Aided Wideband DFRC with Reconfigurable Holographic Surface,”in Proc. IEEE 48th International Conference on Acoustics, Speech and Signal Processing (ICASSP), Rhodes, Greece, Jun. 2023.

● S. Zhao, Y. Liu, L. Wu, J. Rodriguez-Pineiro, X. Yin, and J. Hong,“Recursive UE Localization for a Multi-RIS-Assisted Wireless System in an Obstacle-Dense Environment,”in Proc. 17th European Conference on Antennas and Propagation (EuCAP), Florence, Italy, Mar. 2023.

● B. Wang, Z. Cheng, L. Wu, and Z. He,“Hybrid Beamforming Design for OFDM Dual-Function Radar-Communication System with Double-Phase-Shifter Structure,”in Proc. 30th European Signal Processing Conference (EUSIPCO), Belgrade, Serbia, Aug. 2022.

● T. Wei, L. Wu, K. V. Mishra, and B. Shankar M. R.,“Simultaneous Active-Passive Beamformer Design in IRS-Enabled Multi-Carrier DFRC System,”in Proc. 30th European Signal Processing Conference (EUSIPCO), Belgrade, Serbia, Aug. 2022.

● S. Shi, Z. Cheng, L. Wu, Z. He, and B. Shankar M. R.,“Distributed 5G NR-Based Integrated Sensing and Communications Systems: Frame Structure and Performance Analysis,”in Proc. 30th European Signal Processing Conference (EUSIPCO), Belgrade, Serbia, Aug. 2022.

● L. Wu, M. Alaee-Kerahroodi, and B. Shankar,“Improving Pulse-Compression Weather Radar via the Joint Design of Subpulses and Extended Mismatch Filter,”in Proc. The International Geoscience and Remote Sensing Symposium (IGARSS), Kuala Lumpur, Malaysia, Jul. 2022.

● S. Xu, L. Wu, B. Shankar, and P. Babu,“Integrated Trajectory Optimization and Cubature Kalman Filter for UAV-Based Target Tracking with Unknown Initial Position,”in Proc. IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM), Trondheim, Norway, Jun. 2022.

● T. Wei, L. Wu, K. V. Mishra, and B. Shankar M. R.,“IRS-Aided Wideband Dual-Function Radar-Communications with Quantized Phase-Shifts,”in Proc. IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM), Trondheim, Norway, Jun. 2022.

● Y. Liu, L. Wu, M. Alaee-Kerahroodi, and B. Shankar M. R.,“A 3D Indoor Localization Approach Based on Spherical Wave-front and Channel Spatial Geometry,”in Proc. IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM), Trondheim, Norway, Jun. 2022.

● B. Wang, Z. Cheng, L. Wu, and Z. He,“Hybrid Beamforming Design for Single-User OFDM Dual-Function Radar-Communication System with Space-Frequency Nulls,”in Proc. IEEE Wireless Communications and Networking Conference (WCNC), Austin, TX, USA, Apr. 2022.

● L. Wu, J. Dai, B. Shankar, R. Hu, and B. Ottersten,“Recurrent Design of Probing Waveform for Sparse Bayesian Learning Based DOA Estimation,”in Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Singapore, May 2022.

● T. Wei, L. Wu, K. V. Mishra, and B. Shankar M. R.,“Multi-IRS-Aided Wideband Integrated Sensing and Communications,”in Proc. IEEE JC&S Symposium, Innsbruck, Austria, Mar. 2022.

● X. Cheng, L. Wu, T. Wei, D. Ciuonzo, and W. Wang,“Transmit Signal Design for Polarimetric Radars under Local Waveform Constraints,”in Proc. CIE International Conference on Radar, Haikou, China, Dec. 2021.

● T. Wei, L. Wu, and B. Shankar M. R.,“Sparse Array Beampattern Synthesis via Majorization Based ADMM,”in Proc. IEEE Vehicular Technology Conference (VTC2021-Fall), Online, Sep. 2021.

● T. Wei, L. Wu, M. Alaee-Kerahroodi, and B. Shankar M. R.,“Transmit Beampattern Synthesis for Planar Array with One-bit DACs,”in Proc. International Radar Symposium (IRS), Online, Jun. 2021.

● L. Wu, K. V. Mishra, B. Shankar M. R., and B. Ottersten,“Heterogeneously Distributed Joint Radar Communications: Bayesian Resource Allocation,”in Proc. IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Lucca, Italy, Sep. 2021.

● L. Wu, P. Babu, and D. P. Palomar, “A Fast Algorithm for Joint Design of Transmit Waveforms and Receive Filters,” in Proc. IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Sapporo, Japan, Jul. 2017.