Trajectory Tracking via Millimeter-Wave Passive Sensing

MmWave passive sensing system 

  1. The mmWave transmitter delivers an information-bearing signal via a transmission beam, while two receive beams, namely the reference beam (reference channel) and surveillance beam (surveillance channel), are adopted at the mmWave receiver.
  2. By comparing the signals of both RF chains, the Doppler effect due to target can be detected.
A Dual-Link Millimeter-Wave Passive Sensing System

System implementation

  • mmWave RF front-end: Sivers Semiconductors, “Evaluation Kits (EVK) and Evaluation Boards (EVB),” https://www.sivers-semiconductors.com/5g-millimeter-wave-mmwave-and-satcom/wireless-products/evaluation-kits/, accessed: [2025-5-9]

  • software defined radio: National Instruments, “USRP – 2954,” https://www.ni.com/zh-cn/shop/model/usrp-2954.html, accessed: [2025-5-9].

Passive Handwriting Tracking via Weak mmWave Communication Signals

  • Tracking non-cooperative targets based on communication signals can be applied to contactless human-computer interaction.
  • By estimating Doppler frequencies from multiple links, handwritten trajectories can be reconstructed.
  • Even in scenarios without direct paths, millimeter-level accuracy can still be achieved by utilizing reflections from displays.
NLoS scenario
LoS scenario
Time-Doppler (Rx1)
Time-Doppler (Rx2)
Reconstruction of the handwriting trajectory in NLoS scenario.
The CDF of trajectory estimation error

C. Yu, Y. Luo, R. Chen and R. Wang, “Passive Handwriting Tracking via Weak mmWave Communication Signals,” in IEEE Wireless Communications Letters, vol. 13, no. 3, pp. 874-878, March 2024, doi: 10.1109/LWC.2023.3348875.

MMALERT: MMWAVE LINK BLOCKAGE PREDICTION VIA PASSIVE SENSING​

  • When the LoS path is blocked by moving objects, it can severely jeopardize the stability of mmwave communication links.
  • Achieving highly accurate prediction of blockage duration allows for issuing warnings of link disruptions in advance.

mmAerlt demo

C. Yu, Y. Sun, Y. Luo and R. Wang, “mmAlert: mmWave Link Blockage Prediction via Passive Sensing,” in IEEE Wireless Communications Letters, vol. 12, no. 12, pp. 2008-2012, Dec. 2023, doi: 10.1109/LWC.2023.3304320.

Trajectory Tracking for MmWave Communication Systems via Cooperative Passive Sensing

  • The movement of passive objects induces distinct Doppler frequencies across different channels.
  • By tracking the variations in Doppler frequencies on each channel, both the transmitter location and the motion trajectory of the passive object can be simultaneously estimated.
N:/AA_Research/Draft/ZTE communications/pic/01_ZTE.png01_ZTE
Multilink Cooperative Localization and Trajectory Tracking
Motion Model

Simultaneously achieve decimeter-level trajectory tracking and transmitter localization

C. Yu, B. Lv et al., “Trajectory Tracking for MmWave Communication Systems via Cooperative Passive Sensing, ” in ZTE Communications, 2024, doi: 10.12142/ZTECOM.202403005.