Wideband Spectrum Sensing at Sub-Nyquist Rates

TL;DR

This paper introduces a mixed analog-digital spectrum sensing method for wideband cognitive radio that operates at sub-Nyquist rates, enabling real-time spectrum mapping with minimal resource use and hardware complexity.

Contribution

The paper proposes a novel spectrum sensing approach based on the modulated wideband converter that combines fixed analog front-end, sub-Nyquist sampling, and resource sharing with communication functions.

Findings

Hardware experiments confirm fast and accurate spectrum sensing.

The method operates at rates below Nyquist, reducing hardware complexity.

Shared resources enable simultaneous communication and sensing.

Abstract

We present a mixed analog-digital spectrum sensing method that is especially suited to the typical wideband setting of cognitive radio (CR). The advantages of our system with respect to current architectures are threefold. First, our analog front-end is fixed and does not involve scanning hardware. Second, both the analog-to-digital conversion (ADC) and the digital signal processing (DSP) rates are substantially below Nyquist. Finally, the sensing resources are shared with the reception path of the CR, so that the lowrate streaming samples can be used for communication purposes of the device, besides the sensing functionality they provide. Combining these advantages leads to a real time map of the spectrum with minimal use of mobile resources. Our approach is based on the modulated wideband converter (MWC) system, which samples sparse wideband inputs at sub-Nyquist rates. We report on results of hardware experiments, conducted on an MWC prototype circuit, which affirm fast and accurate spectrum sensing in parallel to CR communication.