A method for monitoring physiological signal characteristics of a living subject is disclosed. A salient idea is to electromagnetically couple the antennas of respectively a networking device and a monitoring device, the networking device transmitting a wireless signal, the monitoring device receiving a first and a second signals from the electromagnetic coupling, the first and the second signals comprising a reflection of the transmitted signal on a living subject as well as a part of the transmitted signal resulting from the antenna coupling. A self-interference cancellation processing is applied to the received first and second signals for extracting the reflected signal from the first signal prior to amplifying and mixing with the received second signal so as to monitor physiological signal characteristics of the living subject.The electromagnetic coupling is advantageous as it allows to pair the monitoring device, being for example a small size sensing module to any existing wireless network piece of equipment and to use existing network traffic as a source diagnostic signal. The self-interference cancelation is further advantageous as it allows to attenuate the large amplitude of the received first and second signals (being large in comparison with the reflected portion of the transmitted signal which is more attenuated through reflection and path losses) before amplifying and mixing so as to avoid a RF saturation of the receiver. This allows to guarantee good RF amplification conditions for the system reception.
