Coherent Backscatter Communications Using Ambient Transmitters and Passive Radar Processing

A method of communications is presented based on the backscatter modulation of terrestrial digital television signals by low-complexity tags. The modulation is sensed by receivers implementing passive coherent detection algorithms similar to those used in passive radar. This method enables shared use of the UHF television band for low-data-rate applications. Analyses and experiments suggest the feasibility of this technique but also highlight the unique challenges for designing such a system.