Breathing rate estimation using radio frequency (rf) sensing

A device comprising:

• a memory;
• and
• one or more processors communicatively coupled with the memory,
• wherein the one or more processors are configured to:
• obtain channel state information (CSI) corresponding to each subcarrier of a plurality of subcarriers in a set of RF transmissions comprising at least the plurality of subcarriers;
• extract phase information of the CSI corresponding to each subcarrier of the plurality of subcarriers over a period of time;
• determine, for each subcarrier of the plurality of subcarriers, a frequency spectrum from the phase information of the CSI corresponding to the respective subcarrier, the frequency spectrum comprising phase change values of the CSI corresponding to the respective subcarrier for a plurality of frequencies;
• determine a breathing rate from the frequency spectrum of the CSI corresponding to a subcarrier set comprising one or more subcarriers of the plurality of subcarriers, the breathing rate corresponding to a phase change value in the frequency spectrum within a predetermined range of frequencies for breathing rates;
• and
• output an indication of the determined breathing rate.

An apparatus for radio frequency (RF) sensing for breathing rate determination, the apparatus comprising:

• means for obtaining channel state information (CSI) corresponding to each subcarrier of a plurality of subcarriers in a set of RF transmissions comprising at least the plurality of subcarriers;
• extracting phase information of the CSI corresponding to each subcarrier of the plurality of subcarriers over a period of time;
• means for determining, for each subcarrier of the plurality of subcarriers, a frequency spectrum from the phase information of the CSI corresponding to the respective subcarrier, the frequency spectrum comprising phase change values of the CSI corresponding to the respective subcarrier for a plurality of frequencies;
• means for determining a breathing rate from the frequency spectrum of the CSI corresponding to a subcarrier set comprising one or more subcarriers of the plurality of subcarriers, the breathing rate corresponding to a phase change value in the frequency spectrum within a predetermined range of frequencies for breathing rates;
• and
• means for outputting an indication of the determined breathing rate.

A non-transitory computer-readable medium storing instructions for radio frequency (RF) sensing for breathing rate determination, the instructions comprising code for:

• obtaining channel state information (CSI) corresponding to each subcarrier of a plurality of subcarriers in a set of RF transmissions comprising at least the plurality of subcarriers;
• extracting phase information of the CSI corresponding to each subcarrier of the plurality of subcarriers over a period of time;
• determining, for each subcarrier of the plurality of subcarriers, a frequency spectrum from the phase information of the CSI corresponding to the respective subcarrier, the frequency spectrum comprising phase change values of the CSI corresponding to the respective subcarrier for a plurality of frequencies;
• determining a breathing rate from the frequency spectrum of the CSI corresponding to a subcarrier set comprising one or more subcarriers of the plurality of subcarriers, the breathing rate corresponding to a phase change value in the frequency spectrum within a predetermined range of frequencies for breathing rates;
• and
• outputting an indication of the determined breathing rate.