Asynchronous mmWave Radar Interference for Indoor Intrusion Detection

This paper describes the development of a system for indoor intrusion detection that takes advantage of interference between asynchronous millimetre-wave radars. The approach exploits the information embedded in the interference pattern observed in the Doppler domain when two or more radars operate in a common environment and share the same frequency spectrum. By continuously monitoring the interference, it is possible to detect the corresponding energy variations. A sharp decrease in the interference energy is thus interpreted as an intrusion of an object or a person. Within this approach the source of the interference can be identified taking advantage of beam-forming of MIMO radars. Compared with the standard configuration, which exploits the reflection of radar signals, the proposed setup has the advantage of maximizing the energy available for intrusion detection and an increased capacity of obstacles and walls penetration. When combined with the capacity of mobile robots to dynamically position the radars, this scheme permits the implementation of highly versatile intrusion detection solutions.