Wireless Digital Key Experimental System

Qiushi Xie^‡, Tuoyuan Zhu, Yachen Pang, Jingyuan Xia^*, Kan Xiao^*

Jul–Aug 2026 · 2026 National Undergraduate Electronics Design Contest (Hubei) · Hubei First Prize

A digital key system using UWB ToF ranging, four-antenna PDoA angle estimation, and Kalman filtering for 4-bit identity verification, real-time three-zone classification, audiovisual greeting, and automatic locking control.

The 2026 contest was held at the provincial level with no national round; First Prize in the Hubei Division was the highest award available that year.

WebsiteProject GitHubCODE

Digital Key System · Principles and ValidationUWB ToF / PDoA · Identity · Zone Control · Smart Lock

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Digital key and smart lock system block diagram — System Loop · UWB transmission, positioning receiver, controller, and lock actuation

Dual-antenna PDoA azimuth estimation principle — Angle Estimation · Direction from phase difference of arrival

Four-antenna UWB receiver structure — Receiver Design · Four-antenna baselines and controller data link

Complete digital key system prototype — Integrated Prototype · 120° positioning base station, lock control, and host software

Digital key unlock-zone runtime interface — Runtime Interface · ID, range, azimuth, zone, and lock state

Digital key software flow — Control Flow · Verification, filtering, zone classification, and actuation

UWB digital key beacon — Digital Key · One-button startup and 4-bit identity beacon

Smart lock actuator — Actuator · Audiovisual greeting, automatic unlock, and exit locking

Localization, identity, and zone test results — Test Results · Localization accuracy, identity verification, and three-zone operation

0.04 mMaximum range error2.3°Maximum azimuth error4 bitConfigurable identity ID6 / 6Correct function decisions

‡ Team lead · * Advisor