Wisconsin Alumni Research Foundation

National Science Foundation

Teng Wei

Xinyu Zhang

Anfu Zhou

Sanjib Sur

Shu Wang

A wireless vibrometer employs an antenna array to significantly boost the signal-to-noise ratio of faint received signals twin small objects vibrating at acoustic frequencies. This technique may be used to provide an improved physiological monitor (such as a pulse detector) or for long-range eavesdropping using the emitted power from a cell phone or the like.

Wireless vibrometer with antenna array

The inventors have recognized that in RF communication systems, by switching between transmit antennas of an RF transmitter on a sub-symbol basis (antenna index coding), and/or by adaptively determining how often antenna switching occurs (adaptive antenna hopping), an increased amount of data may be wirelessly transmitted to an RF receiver without significantly increasing energy consumption. The inventors have determined that in certain systems, such as ZigBee, data symbols consist of elementary waveform patterns, and that such waveform patterns for transmit antennas may be stored by an RF receiver for later determining transmit antennas for data symbols. The inventors have also determined that the invention may be applied in the frequency domain, such as to OFDM, by storing subcarrier waveform patterns for particular transmit antennas and later determining transmit antennas for subcarriers of data symbols.

Growing community of inventors

Madison, WI, United States of America

Teng Wei