Localization of Vital Signs in Indoor Surroundings Using an Active Tag with a Self-Injection-Locked Oscillator
碩士 === 國立中山大學 === 電機工程學系研究所 === 101 === This thesis aims to develop a wireless sensing system for use at 2.4 GHz ISM band in detection of the vital signs and indoor locations of the target subjects. The sensor, an active tag with a self-injection-locked (SIL) oscillator, transmits the carrier signal...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2013
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| Online Access: | http://ndltd.ncl.edu.tw/handle/79395065447240647630 |
| Summary: | 碩士 === 國立中山大學 === 電機工程學系研究所 === 101 === This thesis aims to develop a wireless sensing system for use at 2.4 GHz ISM band in detection of the vital signs and indoor locations of the target subjects. The sensor, an active tag with a self-injection-locked (SIL) oscillator, transmits the carrier signal that is frequency-modulated (FM) by the Doppler signal of the cardiopulmonary activity and the tuning voltage signal of the SIL oscillator; the injection-locked (IL) I/Q receivers perform arctangent demodulation of the FM signal to obtain the subjects’ vital signs and position information. The SIL technology ensures high sensitivity of vital sign detection while the IL I/Q receivers locate the targets without using reference signals. The designed system achieves a minimum of 10 cm location error within an 8-by-8 meter square area in an indoor environment. In the experiment, the frequency division multiple access technology is employed to detect different subjects. Moreover, fidgeting effect on the detection of vital signs has been greatly reduced by a spectral product approach.
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