Methods, apparatus and systems for wireless vital monitoring are described. In one example, a described system comprises: a transmitter configured for transmitting a first wireless signal through a wireless channel of a venue; a receiver configured for receiving a second wireless signal through the wireless channel; and a processor. The second wireless signal comprises a reflection of the first wireless signal by at least one living being having at least one repetitive motion in the venue. The processor is configured for: obtaining a time series of channel information (TSCI) of the wireless channel based on the second wireless signal; generating, for each living being of the at least one living being, a vital signal representing all repetitive motions of the living being based on the TSCI; extracting, from the vital signal of each living being, a heartbeat signal; and monitoring, for each living being in the venue, a heart rate variability based on the heartbeat signal.