Various examples of methods and systems are provided for vibrational frequency detection (e.g., noncontact vital sign detection) using digitally assisted low intermediate frequency (IF) architectures. In one example, a transceiver system is configured to transmit a modulated signal generated by modulating a local oscillator (LO) signal with an IF carrier generate an IF signal by down converting a received signal comprising backscatter with the LO signal and simultaneously sample the IF carrier and the IF signal. A vibration frequency can be determined by demodulating the sampled IF signal with the sampled IF carrier. In another example, a method includes generating and transmitting a modulated signal receiving backscatter of the modulated signal generating an IF signal by down converting the received signal with the LO signal simultaneously sampling the IF carrier and the IF signal and determining a vibration frequency by demodulating the sampled IF signal with the sampled IF carrier.
