Enabling Indoor Multi-Person Tracking With 6G mmWave ISAC Systems

TL;DR

This paper presents a novel 6G mmWave ISAC system for indoor multi-person tracking, utilizing sparse sensing signals and advanced algorithms to achieve high accuracy with minimal sensing overhead.

Contribution

It introduces a new multi-person tracking method with low sensing overhead, combining a modified MTI scheme, target identification, and Kalman filtering with data association.

Findings

Median position error of 12 cm in indoor environments

Sensing overhead less than 0.005% of OFDM frame

Effective tracking during path-crossing scenarios

Abstract

Integrated sensing and communication (ISAC) has emerged as a key technology for 6G wireless networks. In this paper, wireless sensing for the indoor multi-person tracking is explored with 6G mmWave ISAC systems. To limit the sensing overhead, a sparse deployment of sensing reference signals (RS) is applied in the orthogonal frequency-division multiplexing (OFDM) frame, where the channel state information (CSI) at the sensing RS is extracted for the multi-person tracking. To enable a robust tracking of multiple persons in a complex indoor environment, three key mechanisms are proposed: 1) a modified moving target indicator (MTI) scheme is proposed to remove the static environmental clutter under a sparse RS time spacing; 2) an effective target identification mechanism is developed to exclude false target points; 3) the Kalman filter with a penalty association algorithm is designed to associate the detected points with the right tracks, especially handling the crossover case of two tracks. With the above mechanisms, multiple persons can be effectively tracked with an extremely low sensing overhead. An mmWave bistatic ISAC prototype system at 26 GHz with 500 MHz bandwidth has been developed to validate our design, where the overhead of the sensing RS is less than 0.005\%. Experimental results demonstrate that our proposed design achieves a median position error of 12 cm for multi-person tracking with path-crossing in the indoor environment with a single receiver.