ABSTRACT

Spectrum sensing is an essential part of a cognitive radio system. This chapter investigates the major spectrum sensing techniques in both single-band (SB) and multiband cases with an in-depth discussion and comparison between the different approaches. It discusses coherent detection, energy detection, and feature detection, which are among the most well-known algorithms in SB spectrum sensing. The most standard way of sensing the spectrum is the energy detector–based sensing. In practical wireless communication systems, the transmitted signals are deliberately embodied by some unique features to assist the receiver in detection. This type of detection uses the cyclostationary features caused by the periodicity in the signal or in its statistics. Spectrum sensing requires a very high sampling rate, high-resolution analog-to-digital converters (ADCs), and high-speed digital signal processors (DSPs). The chapter describes the multiband detection problem and its typical applications and the best physical-layer candidate for multiband cognitive radio networks (MB-CRNs).