An efficient compressive wideband spectrum sensing architecture for cognitive radios

Abstract

Cognitive Radios (CRs) are expected to enhance spectrum efficiency by enabling dynamic or opportunistic access to underutilized licensed frequency bands. To fully maximize capacity gains, CRs must be able to detect spectral opportunities across a wide spectral band. Realizing a wideband spectrum sensing architecture will require analog-to-digital converters (ADC) with extremely high sampling rates. Currently, however, it is infeasible to achieve such rates using the state of art ADC technologies. On the other hand, compressed sensing (also known as compressive sampling) theory has been introduced as a technique for efficiently acquiring and reconstructing a signal using sub-Nyquist sampling rates. In this paper, we propose a wideband spectrum sensing architecture which employs a recently-proposed compressed sensing technique, “channel multiplexer” with a single low switching rate analog to digital converter and low chipping rate pseudorandom generation circuit. Our proposed architecture offers a simple low-power design with enhanced performance over state-of-art wideband spectrum sensing architectures.