Compressed Sensing Based Radio Architectures for Rapidly Finding Interferers in the Spectral and Spatial Domains
Traditional, high-resolution frequency or direction-of-arrival RF scanners can be slow and consume substantial energy, particularly, if rapid tracking of fast moving signals is required. Compressed sensing (CS) is a novel signal processing solution that enables the reduction in the number of samples required, if the signal being sampled has a known structure, e.g., a relatively small number of signals of interest at unknown locations in a wide bandwidth. Our recent research has shown that CS techniques can drive innovations for RF scanners from the signal processing all the way to the circuit architecture to develop systems that offer better performance envelopes. We have implemented a family of prototype demonstration systems that provide EM environmental awareness using CS. Our Direct RF to Information Converter (DRF2IC) chip demonstrates a very fast spectrum scanner that can detect up to 6 interferers over 1GHz of bandwidth in less than 10us, while requiring up to 6x less energy than classical approaches. Our Direct Space to Information Converter (DSIC) chip has an 8 antenna, CS based, receiver array for direction of arrival (DoA) finding and uses 4x less measurements than current DoA finding methods, again resulting in higher scan speed and lower energy consumption. Moreover, these chips offer unified architectures; the DRF2IC architecture elegantly merges traditional high-performance direct-conversion reception and high-performance CS based scanning; the DSIC unifies a fast DoA scanner with a beamforming receiver. Both the DRF2IC and DSIC are able to switch between scan and receiving mode in microseconds making them suitable for enabling communications in interferer rich environments.