A Nyquist folding analog-to-information receiver

Abstract

Many radar and communications applications require detection and estimation of signal information across an extremely wide radio frequency (RF) bandwidth. In practice, however, direct digitization of this broadband RF environment is problematic. Physical limitations in analog-to-digital converter (ADC) technology restrict the total bandwidth that can be digitized, as well as the ability to digitize high RF signals directly. This paper describes a novel ldquoanalog-to-informationrdquo receiver, motivated by recent developments in compressed sensing (CS), which overcomes both of these challenges in certain settings. The proposed receiver performs frequency modulated pulsed sampling at sub-Nyquist/Shannon rates to compress a broadband RF environment into an analog interpolation filter. The RF sample clock modulation induces a Nyquist-zone dependent frequency modulation on the received signals, allowing separation and recovery of the signal information from a sparse broadband RF environment.