Review: Wideband Spectrum Sensing for Next Generation Wireless Networks

Next generation wireless networks are expected to operate in licensed, shared as well as unlicensed spectrum. To enable this, central controller or base stations need wide-band spectrum sensing (WSS) to periodically identify potential spectrum resources and allocate them to the desired users. The main challenge in WSS is the requirement of prohibitively high sampling rate analog-to-digital converters (ADC) which are area and power hungry. To overcome this bottleneck, sub-Nyquist sampling based WSS (SNS-WSS) techniques have been discussed in the literature. The SNS-WSS exploits the sparse nature of a wideband spectrum and hence, accomplish WSS using low-rate ADCs. In this paper, we review and compare the advantages and drawbacks of existing SNS-WSS. We also discuss future research directions for making SNS-WSS feasible in next generation wireless networks.