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论文类型：期刊论文

发表时间：2021-01-10

发表刊物：IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY

卷号：69

期号：9

页面范围：10242-10251

ISSN号：0018-9545

关键字：Monitoring; Sensors; Multiplexing; Wireless communication; Wireless sensor networks; Receivers; Wireless fidelity; Device-free; wireless sensing; multiplexing mechanisms; multi-target; FMCW

摘要：Device-free wireless sensing (DFWS) is a promising technology which could sense target states without requiring them equipped with any device. In recent years, it has drawn considerable attention due to its potential application in the fields of fatigue driving detection, vital sign monitoring, human-computer interaction, etc. State-of-the-art work has achieved excellent sensing performance when there is one target only. However, when there are multiple targets need to be sensed simultaneously, the influenced signals from different targets will be mixed together, and thus traditional DFWS methods will fail. There still lacks an effective system solution to this problem. Inspired by the multiplexing mechanisms utilized in communication systems, in this paper, we explore and exploit the idea of separating and extracting the influenced signal from each target by leveraging three novel multiplexing mechanisms, i.e., angle division multiplexing sensing, range division multiplexing sensing, and source division multiplexing sensing, and thus realize multi-target DFWS accordingly. Meanwhile, we also give theory analysis on the sensing capability of the proposed multiplexing mechanism based multi-target sensing systems. Furthermore, taking multi-target vital sign monitoring as a case study, we develop a 77 GHz FMCW hardware based prototype system, and evaluate the proposed mechanisms extensively. Experimental results reveal the effectiveness of the proposed mechanisms.