Remote parametric detection and localization of tags

A system comprising:

• an ultrasonic transducer configured to transmit an ultrasound signal towards a tag being located by the system, wherein the tag is passive, wherein the tag does not include a battery and/or a powered or an active component;
• an antenna configured to transmit a first radio frequency signal towards the tag and receive a second radio frequency signal from the tag, the second radio frequency signal including a modulation of at least a portion of the first radio frequency signal by creating a sideband caused by the ultrasound signal received by the tag;
• and
• detection circuitry to detect the modulation and configured to:
• filter the second radio frequency signal to isolate the sideband corresponding to a frequency of the ultrasound signal transmitted by the ultrasonic transducer;
• convert the sideband to a baseband representation;
• perform matched filter detection on the baseband representation to generate a matched filter output;
• and
• provide an indication of a distance to the tag based on a time of travel associated with the sideband, wherein the time of travel is based on a time of a peak of the matched filter output, and
• wherein the detection circuitry further includes a self-interference cancellation circuitry to remove self-interference portion of the second radio frequency signal prior to demodulation of the second radio frequency signal.

A method comprising:

• transmitting a first signal towards a tag being located, the first signal comprising an ultrasound signal generated by an ultrasonic transducer and/or an optical signal generated by an optical emitter, wherein the tag is passive, wherein the tag does not include a battery and/or a powered or an active component;
• transmitting, by at least one antenna, a first radio frequency signal towards the tag;
• receiving a second radio frequency signal from the tag, the second radio frequency signal including a modulation of at least a portion of the first radio frequency signal by creating a sideband caused by the ultrasound signal that is received by the tag and/or the optical signal that is received by the tag;
• detecting the modulation;
• filtering the second radio frequency signal to isolate the sideband corresponding to a frequency of the ultrasound signal transmitted by the ultrasonic transducer;
• converting the sideband to a baseband representation;
• performing matched filter detection on the baseband representation to generate a matched filter output;
• and
• providing an indication of a distance to the tag based on a time of travel associated with the sideband, wherein the time of travel is based on a time of a peak of the matched filter output.